8. She bought her son two __________ pencils.
A. dozen of B. dozens
C. dozen D. dozens of
答：C．dozen与数词连用，不用复数，另外dozen后一般不与of连用，若接of时，后应有the，these，those等限定词或them，如I want three dozen of the / these / those pencils或I want three dozen of theme。
9. _________cave that George has discovered in his lifetime is near the Alps.
A. The hundredth B. The hundred
C. Hundredth D. A hundredth
答：A。第一百个，序数词前应用定冠同。
10. Mr Smith_________ me to buy several _________ eggs for the dinner party.
A. asked, dozen B. suggested, dozens of
C. had, dozen D. persuaded, dozens
答：A. dozen 与several, many及数词连用时，不用复数形式，后也不接of，如three dozen pencils。
11. The children often go to school_____.
A. by two and three B. by two or three
C. by twos and threes D. by twos or threes
答：C。 bytwosand threes 三三两两地
12. She waters the flower
A. each three days B. every third days
C. every three days D. each other day
答：C。每几天，不用each来表示，应说every few days；每三天every three days 或every three days; 每隔一天every other day。
13. He will be back in_________.
A. a or two days B. one or two days
C. one day and two D. one and two day
答：B。“一两天”可以说成 one or two days 或 a day or two。
14. He’s been here for_______.
A. one and a half hours
B. one and half an hour
C. one and half hours
D. one and a half hour
答：A。“一个半小时”可以说成 an hour and a half或 one and a half hours,
15. The working women in the city got paid_________.
A. by hours B. by an hour
C. by hour D. by the hour
答：D．表示按小时、天、月、打等单位的词应这样表示：by the hour / day / month / dozen; 表示按长度、重量应这样表示：by length / weight.
16. I’ve already covered ___________ pages of the book.
A. he first twenty B. a twenty first
C. the twenty first D. a flrst twenty
答；A．头二十页the first twenty pages，后二十页the last twenty pages，头几天the first few days。
17．We’ll stay here for_________.
A. other ten days B. another ten days
C. another ten day D. ten another days
答：B。“再用十天时间”可以说成another ten days或ten more days．
18. ________broke out in 1939.
A． World War Second
B. The World War Second
C. Second World War
D. World War Two
答：D。“第二次世界大战”可以说成World War Two或The Second World War。“第一单元”可说成Unit One或The First Unit。
19．He lives in_________.
A. Room 311 B. 311 Room
C. the 311 Room D. the Room 311
答：A。表示“在几号房间”习惯上用“Room+房间号”。
20．The earth is nearly_________the moon.
A. 50 time the size of B. 50 times the size of
C. 50 times as bigger as D. as big as 50 times
答：B。表示A是B的多少倍可以说A isk... times the size / length / height / weight / width of B。或A is ... times as big / long / hight as B。