题目内容
线缆传输的衰减量会随着长度和频率的增加而增大。
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衰减时传输所造成的信号损耗,以分贝(dB)表示。
串扰是两条信号的耦合,信号线之间的互感和互容引起线上的扰乱。
I. Blank filling: Confusable words (近义词辨析)(Directions:) Fill in the blanks with the words. Change the form where necessary (必要时改变单词的形式，如时态、单复数).Group 1ban, forbid, prohibit1. In some countries the sale of alcoholic beverages is _____. 在一些国家禁止出售含酒精的饮料。2. The treaty ____ all nuclear tests. 该条约禁止一切核试验。3. He _____ his children sweets because he didn’t want their teeth to be ruined. 他不许孩子们吃糖果，因为他不希望他们的牙齿蛀坏。Group 2invent, discover4. The planet Pluto was ______ in 1930. 冥王星是在1930年被发现的。5. Alexander Graham Bell ______ the telephone. 亚历山大•格雷厄姆•贝尔发明了电话。Group 3descend, fall, drop6. The rain was still __________ from the trees.7. On turning the corner, we saw that the road ______ steeply.8. Large masses of rock are constantly ______ into the sea.9. The hawk (鹰) ______ in a vertical stoop on its quarry (猎物).Group 4conquer, beat, defeat10. She ______ her brother at tennis. 在网球上，她打败了她弟弟。11. The Romans _____ parts of Britain in the first century B. C. 公元前一世纪罗马人曾占领了英国的部分领土。12. He was _____ by 165 votes against 132. 他以132票对165 票落选了。Group 5source, origin13. They had to find a new ______ of income. 他们不得不寻找新的收入来源。14. There are a number of words in the English language which were French in __________.15. Where is the _______of the River Thames?16. They had to find a new _________ of income.17. This practice owes its _________ to the Chinese.
II. Blank filling (选词填空 填单词对应字母,如：A)A. Strictly speaking B. mysteryC. resembles D. source E. for effectF. invadedG. conquered H. fascinating I. elite J. surrenderedK. put into practice L. alternative M. aroused N. snackO. climateP. drifted1. ______________________, he is not a southerner. His biography reveals that, though born in the south, he spent a good part of his childhood years in New England.2. Right after the Spring Festival, millions of young people _________ from the countryside to the cities to look for work and explore the world.3. It is obvious that Tom _____________ his father both in appearance and in character.4. There is clear evidence that Japan committed many serious crimes against the Chinese people when it ____________ China during the Second World War.5. Medical scientists expect it will be many years before cancer is ________________.6. The novel has a _________________ plot. This explains why it has remained number one on the best-seller list for so long.7. He must have been very busy these days. He does not go out for lunch but eats a ________ in the office.8. To settle the controversy, we have to ______ all these different theories _________ to see which one works better.9. The information is supposed to have come from a reliable ________.10. We rarely have such terrible weather. The ____________ here is usually very mild and everything thrives in this region.11. People felt relieved when the invaders finally put down their arms and ________________.12.Our suspicions were first _____________ when the two other parties made a deal behind our backs.
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