Bài ôn tập môn học Tiếng Anh khối 11 - Unit 9 đến unit 16

A. READING
equip [i'kwip] with(v) trang bị 	 →equipment [i'kwipmənt] (n) thiết bị, sự trang bị 
 advanced [əd'vɑ:nst](a) tiên tiến →advancement [əd'vɑ:nsmənt] (n) sự tiến bộ 
spacious ['spei∫əs] (a) = roomy : rộng rãi →space ['speis] (n) không gian 
well-trained (a) = skilled : 	 lành nghề 
 staff (n):	 (toàn thể) nhân viên 
 thoughtful ['θɔ:tfl] (a) chín chắn, sâu sắc # thoughtless ['θɔ:tlis](a) không suy nghĩ 
courteous ['kə:tjəs] (a) = polite : lịch sự →courtesy (n) lịch sự 
 →courteously ['kə:tjəsli] (adv): một cách lịch sự 
mail and parcel service (n) dịch vụ chuyển thư và bưu phẩm 
surface mail ['sə:fis] (n) thư gởi bằng tàu ,xe 
EMS (Express Mail Service): dịch vụ thư chuyển phát nhanh 
weight limit ['weit] (n) trọng lượng giới hạn 
Express Money Tranfer chuyển tiền nhanh 
speedy ['spi:di] (a) = nhanh chóng ←speed (n) tốc độ 
secure [si'kjuə] (a) bảo đảm, an ninh → security [si'kjuərəti](n) sự an ninh/ an toàn 
transfer ['trænsfə] (v) chuyển (n) sự chuyển →transferance (n) sự chuyển đi 
 →transferable [træns'fə:rəbl] (a) có thể chuyển đi
Messenger Call Service (n) dịch vụ điện thoại 
notify ['noutifai] (v) thông báo → notification [,noutifi'kei∫n] (n) sự thông báo
 → notifiable (adj) phải khai báo 
 recipient (n) người nhận 
 shape (n) hình dạng 
 shapeless (n) không hình dạng, dạng gốc
facsimile [fæk'simili] (n) = fax (n) bản sao , máy fax 
transmission [trænz'mi∫n] (n) sự chuyền đi ← transmit (v) truyền đi 
graphics (n) đồ họa, bức họa 
press distribution [,distri'bju:∫n] (n) sự phát hành báo chí 
subscribe (v) đăng kí (mua báo) → subscription (n) sự đăng ký 
 → subscriber [səb'skraibə] (n) người đăng ký (thuê bao điện thoại, đặt mua báo dài hạn..)
B. SPEAKING
install [in'stɔ:l] (v) 
 → installation [,instə'lei∫n] (n)
take place (v)diễn ra, tiến hành
register ['redʒistə](v) đăng ký 
 → registration [,redʒi'strei∫n] (n):
C. LISTENING
Commune ['kɔmju:n] (n): 
→ communal ['kɔmjunl] (a): chung, công cộng
Rural ['ruərəl](a) : thuộc nông thôn
Digit ['didʒit] (n): con số
Capacity [kə'pæsiti](n): khả năng sản xuất, sức chứa
Upgrade [ʌp'greid] (v):cập nhật 
Telecommunication [,telikə,mju:ni'kei∫n] (n) viễn thông
Reduce [ri'dju:s]: giảm (v) → reduction (n)
Unit 9 THE POST OFFICE 
subscribers – networks - upgrading - customer demand - rural areas
Over the past few years, Vietnam has quickly developed its telephone system.
Vietnam ranks second only to China for growth in the number of telephone (1) .. . It is among the 30 countries in the world that have more than two million telephone subscribers.
In the early 1990s, there were only 140,000 telephones across Vietnam. At present, we have more than six million subscribers.
In 1996, Vietnam began (2).. its fixed telephone (3)  and changing numbers from six to seven digits in Hanoi and Ho Chi Minh City as well as five to six digits in other provinces .
Five years later, the mobile phone system was upgraded to meet the growth in 
 (4) .. since 2000 , Vietnam has reduced the price of several services, especially in the monthly fees for fixed and mobile telephones .
In the future, more attention will be paid to the (5) . At present, 93 percent of communes across Vietnam have telephone services .A network of 6,014 communal post offices have been set up across the country.
D. WRITING 
quality ['kwɔliti] (n): chất lượng
attitude ['ætitju:d] (n): thái độ
punctuality [,pʌηkt∫u'æləti] (n): sự đúng giờ → punctual ['pʌηkt∫uəl] (a): đúng giờ
arrogant ['ærəgənt] (a): kiêu ngạo 
pickpocket ['pik,pɔkit] (n): kẻ móc túi 
deliver [di'livə](v) → delivery [di'livəri] (n)
resident ['rezidənt](n): người dân
Record: Father & Son Ltd, good morning for Sales press one. For Account press two. For enquiries, please hold.
Dona : Father & Son company , Thank you for __________ . This is Dona speaking. How can I help you? 
Georgia: Hello, my name is Georgia King, I’d like to speak to Jon Barnes, please.
Dona : Sorry , what __________ is that ?
Georgia: It’s Georgia King speaking.
Dona: Oh, I’m afraid Mr. Barnes isn’t here at the moment. Can I take a __________?
Georgia: Well, I’m returning his call. He left me a message to call him.
Dona : Ok, Hold on please  The line’ s _____________ at the moment . Can you call Mr. Barnes back later?
Georgia: Um, Can I leave a message please ?
Dona: Oh, just a minutes. I’ll put you _________ to one of his colleagues.
A.READING
endangered [in'deindʒərd]( (a) bị nguy hiểm ← endanger [in'deindʒə(r)](v) gây nguy hiểm
 → endangerment (n) sự gây nguy hiểm 
species ['spi:∫i:z] (n) chủng loài
cheetah ['t∫i:tə] (n) báo gấm 
estimate ['estimit - 'estimeit] (v) ước tính → estimation (n) sự ước tính
 panda ['pændə] (n) gấu trúc 
influence ['influəns] (v,n) ảnh hưởng →influential [,influ'en∫əl] (a) có ảnh hưởng 
pollute [pə'lu:t] (v) =contaminate : làm ô nhiễm
 → pollution (n) sự ô nhiễm → polluted (a) bị ô nhiễm 
 → pollutant (n) chất gây ô nhiễm 
 respect (n) =aspect: phương diện, 
result in (v) =cause : gây ra, đưa đến 
consequence ['kɔ:nsikwəns] (n) =result (n): hậu quả 
rare ['reə] (a) quý hiếm
 as a result (prep) = therefore : do đó 
 extinct (a) tiệt chủng →extinction [iks'tiηk∫n] (n) 
prohibit [prə'hibit] (v) ban, cấm → prohibition [,prouhi'bi∫n](n) sự cấm
interfere [,intə'fiə](v) can thiệp → interference [,intə'fiərəns](n) 
survive [sə'vaiv] (v)sống còn, sống sót → survival [sə'vaivl](n) :sự sống còn
off – spring (n) con cháu , dòng dõi
 co-exist (v) chung sống , cùng tồn tại → co-existence (n) 
dinosaur [dainə's ɔ:r](n) khủng long 
 fur [fə:] (n) lông (mao) bộ lông 
capture ['kæpt∫ər] (v) sự bắt giữ
recreate [,rekri'ei] (v) làm giải khuây → recreation [,rekri'ei∫n] (n) sự giải trí ,sự tiêu khiển 
 → recreational [,rekri'ei∫ənl] (a)thuộc giải trí 
cultivaion [,kʌlti'vei∫n] (n) sự canh tác ← cultivate ['kʌltiveit](v) trồng trọt 
 → cultivated (adj) có trồng trọt 
discharge [dis't∫a:] (n) sự tuôn ra / đổ ra 
 measure ['meʒə] (n)= action : hành động , biện pháp 
discourage [dis'kʌridʒ] (v) làm nản chí # encourage (v) khích lệ 
discouragement [dis'kʌridʒmənt] (n) 
 impact ['impækt] (n) = influence : tác động , ảnh hưởng 
scenic feature ['si:nik 'fi:t∫ə] (n) đặc điểm cảnh vật
 devastate ['devəsteit] (v) = destroy : tàn phá 
devastation [,devəs'tei∫n] (n) = destruction(n) 
 approximately (a) nearly, almost : gần như 
maintain [mein'tein] (v) bảo trì → maintainable [mein'teinəbl] (a) có thể bảo trì 
maintenance ['meintinəns] (n) sự bảo trì
preserve [pri'zə:v] (v) gìn giữ / bảo tồn → preservation [,prevə'vei∫n] (n) → preservable [pri'zə:vəbl] (a) có thể bảo tồn 
currently ['kʌrəntli] (adv) at the present time: 
abundant [ə'bʌndənt] (a) = plenty : phong phú → abundancy (n) sự phong phú 
snore [sn ɔ:] (v) ngáy (ngủ) 
grateful ['greitful] (a) biết ơn →gratitude ['grætitju:d] (n) lòng biết ơn 
 owe (v) nợ 
 be blamed for (v) đáng khiển trách
C. LISTENING
Unit 10 NATURE IN DANGER C . LISTENING
 preserve – in danger of - approximately – completely - devastating 
In many parts of the United States , large areas of land have been made into national parks to protect and (1) . the natural beauty of the land . National parks usually contain a variety of scenic features, such as mountain, cakes, lakes, rare animals and plants. Today, there are 52 national parks in the United States, covering (2) .. . 3 per cent of the total land area of the country. National parks are all open to the public and have millions of visitors each year.
Many national parks, however, are (3)being destroyed. Rare animals in national parks are killed or hunted for fur, skin or other parts. Trees are cut down for wood. Large areas of national parks also experience (4)  fires caused by careless people . The increasing number of visitors is harming the parks due to the pollution from their vehicles.
If these problems are not solved immediately , and if there is not enough money for the parks’ staff and maintenance of their resources , many national parks will be (5) . destroyed . 
A. READING
alternative [ɔ:l'tə:nətiv] (a) thay thế
available [ə'veiləbl] (a) sẵn có
dam (n) đập (ngăn nước)
electricity [i,lek'trisiti] (n) điện
energy ['enədʒi] (n) năng lượng
exhausted [ig'z ɔ:stid] (a) cạn kiệt
fossil fuel ['f ɔ sl fjuəl] (n) nhiên liệu hóa thạch
geothermal heat [,dʒi:ou'θə:məl hi:t] (n) địa nhiệt
infinite ['infinit] (a) vô hạn
make use of (exp) tận dụng
nuclear energy ['nju:kliə] (a) năng lượng hạt nhân
plentiful ['plentifl] (a) nhiều
power demand (n) nhu cầu sử dụng điện
release [ri'li:s] (v) phóng ra
reserve [ri'zə:v] (n) trữ lượng
solar energy ['soulə] (n) năng ượng mặt trời
solar panel ['pænl] (n) tấm thu năng lượng mặt trời
windmill ['winmil] (n) cối xay gió
convenient [kən'vi:njənt] (a) tiện lợi
enormous [i'n ɔ:məs] (a) to lớn, khổng lồ
harmful ['h ɑ:mful] (a) có hại
hydroelectricity [,haidrouilek'trisiti] (n) thủy điện
nuclear reactor [ri:'æktə] (n) phản ứng hạt nhân
radiation [,reidi'ei∫n] (n) phóng xạ
renewable [ri'nju:əbl] (a) có thể thay thế
run out (v) cạn kiệt
ecologist [i'k ɔlədʒist] (n) nhà sinh thái học
ecology (n) sinh thái học
fertilize ['fə:tilaiz] (v) bón phân
replace [ri'pleis] (v) thay thế
consumption [kən'sʌmp∫n] (n) sự tiêu thụ 
make up (v) chiếm (số lượng)
conduct ['k ɔndʌkt] (v) tiến hành
experiment [iks'periment] (n) cuộc thí nghiệm
extraordinary [iks'trɔ:dnri] (a) lạ thường
locate [lou'keit] (v) nằm ở → location (n) vị trí
progress ['prougres] (n) sự tiến triển 
surround [sə'raund] (v) bao quanh
C. LISTENING
Unit 11 SOURCES OF ENERGY . 
 renewable – Ecologists - fertilized – unlimited – supply - nonrenewable - correct amount 
The natural environment includes all natural resources that are necessary for life the air, the oceans, the sun, and the land. Because they are vital for life, these resources must be protected from pollution and conserved. (1) .. study their importance and how to use them carefully.
According to ecologists, resources are divided into two groups: (2) .. and nonrenewable .When a resource is used , it takes some time to replace it . If the resources can be replaced quickly, it is called renewable. If it cannot be replaced quickly and easily, it is nonrenewable. For example, grass for animals is a renewable resource. When cows eat the grass, the resource is used. If the soil is (3)  and protected, more grass will grow. Coal, However, is (4)  because it takes millions of years to make coal. All fossil fuels are nonrenewable resources.
Solar energy, air and water are renewable resources because there is an (5) .. (6) .However, this definition may change if people are not careful with these resources. The amount of solar energy that reaches the Earth depends on the atmoshere. If the atmosphere is polluted, the solar energy that reaches the earth may be dangerous. If life is going to continue, the air must contain the (7) . of nitrogen (N), oxygen (O), carbon dioxide 
(CO2) a ... ture has many ways of conserving and controlling water. Water can be held on the land by planting vegetation. Forests and grass should be planted where there are no natural growths. Dams built across rivers help hold back the water. Reservoirs behind the dams store water during wet seasons for use in dry seasons. Dams help prevent floods by controlling the flow of water. 
advance [əd'vɑ:ns] (v) tiến bộ
appreciate [ə'pri:∫ieit] (v) đánh giá cao
aquatic sports [ə'kwætik spɔ:t] (n) các môn thể thao dưới nước
athletics [æθ'letik] (n) điền kinh
billiards ['biljədz] (n) 
bodybuilding (n) thể dục thể hình
cycling ['saikliη] (n) đua xe đạp
decade ['dekeid] (n) thập kỷ
enthusiasm [in'θju:ziæzm] (n) sự hăng hái, nhiệt tình
facility [fə'siliti] (n) tiện nghi
fencing ['fensiη] (n) đấu kiếm
hockey ['hɔki] (n) khúc côn cầu
host country (n) nước chủ nhà
intercultural knowledge [,intə 'kʌlt∫ərəl] (n) kiến thức liên văn hóa
mountain biking (n) đua xe đạp địa hình
purpose ['pə:pəs] (n) mục đích
rugby ['rʌgbi] (n) môn bóng bầu dục
shooting ['∫u:tiη] (n) bắn súng
solidarity [,sɔli'dærəti] (n) tình đoàn kết
squash [skwɔ∫] (n) môn bóng quần
weightlifting ['weit liftiη] (n) cử tạ
wrestling ['resliη] (n) đấu vật
karatedo [kə'rɑ:tidou] (n) võ karatê
freestyle ['fri:stail] (n) kiểu bơi tự do
gymnasium [dʒim'neizjəm] (n) phòng thể dục dụng cụ
gymnast ['dʒimnæst] (n) vận động viên thể dục
gymnastics [,dʒim'næstiks] (n) môn thể dục dụng cụ
high jump (n) nhảy cao
long jump (n) nhảy xa
record ['rekɔ:d] (n) kỷ lục
promote [prə'mout] (v) quảng bá
recruit (v) tuyển
upgrade [ʌp'greid] (v) nâng cấp
widen ['waidn] (v) mở rộng → wide (a) rộng
book (v) mua vé trước
C .LISTENING
Unit 12 THE ASIAN GAMES
freestyle – Gymnasium - gold medal - competed - coming from –
Good evening, It’s 10:15 and it’s time for “The Asian Games Report”. It’s the 3rd days of the Games Well, today’s most important event was the women’s 200 metre (1) . The Japanese, Yuko was first and got the (2).. . She made a new world record time of 1 minute 58 seconds. The Japanese athletes won two gold medals yesterday, and three the day before, so in the first three days they’ve won six gold medals. Here we’re in the (3). . LiLy, the Chinese gymnast, has just finished her display. She’s got an average of 9.5 points. That’s the best score today! Lily’s won the gold medal. And this is Lee Bong Ju coming from Korea. This is the second time he (4) . in the long jump at the Asia games. Last time he jumped 8.5 metres .Today he’s won a gold medal for men’s long jump. He jumped 8.9 metres.
 Now we’re waiting for the last high jumper, Vichai (5) .. Thailand. The bar is at 2.30 metres and . It seems too high for him. Vichai has just jumped!  Ooh, He’s crashed into the bar. He’s landing. The bar has fallen too. He’s getting up and walking away. But he’s very disappointed 
A.READING
accompany [ə'kʌmpəni] (v): đệm đàn
accomplished (a) [ə'kʌmpli∫t]: có tài, cừ khôi
admire (v) [əd'maiə]: ngưỡng mộ
avid (a) ['ævid]: khao khát, thèm thuồng
collect (v) [kə'lekt]: sưu tập → collection (n) [kə'lek∫n]: bộ sưu tập
 →collector (n): người sưu tập
discard (v) [di,skɑ:d]: vứt bỏ
fish tank (n): bể cá
indulge IN (v) [in'dʌldʒ]: say mê
modest (a) ['mɔdist]: khiêm tốn
occupied (a) ['ɒkjʊpaied]: bận rộn
tune (n) [tju:n]: giai điệu
broaden (v) ['brɔ:dn]: mở rộng (kiến thức) → broad (a) rộng
category (n) ['kætigəri]: loại, hạng, nhóm
classify (v) ['klæsifai]: phân loại
name tag (n): nhãn ghi tên
bygone (a) ['baigɔn]: quá khứ, qua rồi
cope WITH (v): đối phó, đương đầu
fairy tale (n) ['feəri teil]: chuyện cổ tích
gigantic (a) [dʒai'gæntik]: khổng lồ
ignorantly (adv) ['ignərəntli]: ngu dốt, dốt nát
profitably (adv) ['prɔfittəbli]: có ích
 C. LISTENING Unit 13 HOBBIES 
My Hobby
 interesting – human achievements - wanted – disease - better equipped 
My hobby is reading. I read story books, magazines, newspapers and any kind of material that I find (1) .. . My hobby got started when I was a little boy. I had always (2) . my parents to read fairy tales and other stories to me. Soon they got fed up with having to read to me continually. So as soon as I could, I learned to read. I started with simple ABC books. Soon I could read simple fairy tales and stories. Now I read just about anything that is available.
Reading enables me to learn about so many things. I learned about how people lived in bygone days. I learned about the wonders of the world, space travel , (3)  , gigantic whales, tiny viruses and other fascinating things .
The wonderful thing about reading is that I do not have to learn things the very hard way. For example, I do not have to catch a (4)  to know that it can kill me. I know the danger so I can avoid it. Also I do not have to go deep into the jungle to find out about tigers. I can read all about it in a book.
Books provide the reader with so many facts and so much information. They have certainly helped me in my daily life. I am (5) . to cope with living. Otherwise, I would go about ignorantly learning things the hard way. So I continue to read. Reading is indeed a good hobby.
Television is one of man’s most important means of communication. It brings pictures and sounds from around the world into millions of homes. A person with a television set can sit in his house, and he can watch the present make a speech or visit a foreign country. He can see a war happening and watch statesmen try to bring about peace. Through television, home viewers can see and learn about people, places and things in far-away lands. Television also provides more entertainment programmes than any other kind. The programmes include plays or dramas, light comedies, sporting events and motion pictures, so television now plays an important role in many people’s lives. It is more convenient as well as cheaper for people to sit comfortably at home than to go out. 
A. READING
lift off (v): phóng lên
approximately [ə'prɔksimitli] (adv): khoảng chừng (about)
orbit ['ɔ:bit] (n): quỹ đạo
speed (n) tốc độ
cosmonaut ['kɔzmənɔ:t] (n) = astronaut ['æstrənɔ:t] (n): phi hành gia, nhà du hành vũ trụ 
weightlessness (n) : tình trạng không trọng lượng
enormous [i'nɔ:məs] (a) to lớn, khổng lồ
uncertainty [ʌn'sə:tnti] (n): sự không chắc chắn → uncertain (a)
precisely (adv) : một cách chính xác ← preciseness (n) [pri'saisnis]: 
react (v) phản ứng lại
extreme [iks'tri:m] (a): vô cùng, tộ bậc → extremely (adv)
temperature ['temprət∫ə] (n): nhiệt độ 
psychology [sai'kɔlədʒi] (n): tâm lý → psychological [,saikə'lɔdʒikl] (a) : thuộc về tâm lý
tension ['ten∫n] (n): sự căng thẳng
technical failure ['teknikl] ['feiljə] (n): sự cố kỹ thuật
hero ['hiərou] (n): người anh hung
venture ['vent∫ə] (n) : việc mạo hiểm
feat [fi:st] (n): chiến công, kỳ công
tragic ['trædʒik] (a): bi thảm, bi kịch
occurr (v) xảy ra → occurrence (n) [ə'kɜrəns]
routine [ru:'ti:n] (a) thường lệ
raise [reiz] (v) nêu lên
spacecraft ['speis'krɑ:ft] (n) tàu vũ trụ = spaceship (n)
honour ['ɔnə] (v) : ca ngợi
C. LISTENING Unit 15 SPACE CONQUEST 
challenged – astronauts - collected soil - launched – efforts
In a speech to the Congress in 1961, the US President Kennedy (1)  the nation to put a man on the moon before the end of the decade. After the president’s speech, NASA’s Apollo programme was developed to meet the challenge.
Only July 16, 1969, the Apollo 11 was (2) .. . The astronauts on board of the spacecraft were Neil Armstrong, Buzz Aldrin and Michael Collins.
On July 20, 1969, Neil Armstrong became the first man on the moon. He was followed by Aldrin 40 minutes later. To walk on the moon’s surface, the (3) .. needed to wear a spacesuit with a portable life support system. This controlled the oxygen, temperature and pressure inside the spacesuit. 
Armstrong and Aldrin spend a total of two and a half hours on the moon’s surface. They performed a variety of experiments and (4) .. and rock samples to return to Earth. An American flag was left on the moon’s surface as a reminder of the achievement.
The crew of Apollo 11 returned to Earth on July 24, 1969. They successfully completed their historic mission. It is regarded as one of the greatest human (5) . in the history of mankind.
A. READING
pharaoh ['feərou] (n): Vua Ai Cập cổ
tomb [tu:m] (n): ngôi mộ 
transport ['trænspɔ:t](v): vận chuyển
treasure ['treʒə] (n): kho báu
base [beis] (n): nền móng
burial ['beriəl] (n): sự mai tang ← bury (v) mai táng, chon
chamber (n): buồng, phòng
circumstance ['sə:kəmstəns] (n): tình huống
construction [kən'strʌk∫n] (n): công trình; sự xây dựng ← construct (v)
proceed [prə'si:d] (v): tiến hành
theory ['θiəri] (n) lý thuyết: giả thuyết
propose [prə'pouz](v): đề xuất, đưa ra
enclose [in'klouz] (v): dựng tường, rào (xung quanh cái gì)
mandarin ['mændərin] (n): vị quan
man-made (a): nhân tạo
mysterious [mis'tiəriəs] (a): huyền bí, bí ẩn
pyramid ['pirəmid] (n): kim tự tháp
spiral ['spaiərəl](a): hình xoắn ốc
surpass [sə:'pɑ:s] (v): vượt qua, trội hơn 21. wonder (n): kỳ quan
C. LISTENING
Unit 16 : THE WONDERS OF THE WORLD 
THE GREAT WALL OF CHINA
considered – purposes - stretches - magnificence - prefer to - excitement
The Great Wall of China, which is said to be visible from the moon, winds up and down across deserts, grasslands and mountains of 5 provinces. It is (1) .. one of the greatest man- made wonders in the world thanks to its (2) . and significance . In 1987, the Great Wall was listed as a World Heriatge by UNESCO.
The Great Wall as we see today was mostly built during the Ming Dynasty for defence (3)  It started in 1368 and took 200 years to complete. Some parts of the wall are much older and go back to around 200 B.C. It (4) .. for about 6,000 km from east to west .The wall is about 11 metres high and a stone roadway runs along the top of it .
The Great wall is a symbol of the Chinese nation throughout history. If you (5) . see the wall in a relatively natural state, you’d better go to the northwest of Beijing. This part of the wall is the best choice for it is still in its original state. A visit to the Great Wall will certainly bring tourists great (6) in each step of the wall.
On 4th October, 1957 Moscow radio broadcast the news of the tremendous _______________, the former Soviet Union lauched the world’s first artificial satellite.The Russian word “sputnik”in one day became an ______________ word. Since that time, the former Soviet Union has __________ many other heavier sputniks and rockets to trail the path of man to the planets and the ________.
 The whole world was waiting for the first manned space flight. Few people doubted that it would happen in the former Soviet Union. Nevertheless, the actual ________ came as a complete surprise. On 12th April 1961 a Soviet pilot, Yuri Gagarin, took mankind’s first step into _______. This historical event has proved that man reach out and touch the distant stars and _________ the secrets of the univers .