CO含量达到( )以上，将会导致CO中毒。A．10% B．20% C．30% D． 发布时间：2018-05-27 04:52 │ 来源：www.tikuol.com 题型：单项选择题 问题： CO含量达到( )以上，将会导致CO中毒。A．10%B．20%C．30%D．40%
题型：单项选择题 完形填空。 The computer is a very wonderful machine today, and it's so 1 that it seems that we 2 live or work without it. Computers are used in many 3 , such as offices, factories, big shops, schools and even homes. With the computer people are living a better 4 . The computer is one of the greatest inventions in the 5 century. The first computer was built in America in 1945 which was named ENIAC, and it was not only very 6 , but also quite heavy. It was as big as ten ordinary (普通的) rooms! But the computer is developing very fast. Today they're becoming smaller and smaller, lighter and lighter, and 7 faster and faster. There are so many kinds of different computers in the market that you can choose one that you like best. The computer can do a lot of things for people, and it also helps us to learn about the real world. With the computer you can 8 an e-mail just in a few seconds to your friend far away, but if you post the letter, it will take your friend quite a long time to receive your 9 . Now you can see the computer really gives us a very nice picture about the world of tomorrow. So as a student in the 21st century, you have to work hard and learn how to 10 the computer very well. Don't you think so? ( ) 1. A. beautiful ( ) 2. A. can ( ) 3. A. roads ( ) 4. A. life ( ) 5. A. 18th ( ) 6. A. useful ( ) 7. A. studying ( ) 8. A. give ( ) 9. A. letter ( ) 10. A. get B. interesting B. can’t B. streets B. friend B. 19th B. large B. teaching B. take B. book B. use C. useful C. must C. crossings C. family C. 20th C. small C. walking C. post C. help C. read D. enjoyable D. mustn’t D. places D. country D. 21st D. cheap D. working D. send D. message D. write 查看答案