1．we don't know its value until we lose health.
__not__ __until__ __we__ __lose__ __health__ __do__ we know its value.
2．i will never forget you as long as i live.
__never__ __will__ i forget you as long as i live.
3．i had no sooner gone out than it began to rain.
__no__ __sooner__ __had__ __i__ __gone__ __out__ than it began to rain.
4．we can improve our english only in this way.
__only__ __in__ __this__ __way__ __can__ __we__ improve our english.
5．we have so much homework to do that we have no time to take a rest.
__so__ __much__ __homework__ __do__ we have to do that we have no time to take a rest.
6．if it had not been for your help, i would have been late for school.
__had__ __it__ __not__ __been__ for your help, i would have been late for school.
1．either you or the headmaster __is__ (be) to hand out the prizes to those gifted students at the meeting.
2．the teacher, with 6 girls and 8 boys of her class, __was_visiting__ (visit) a museum when the earthquake struck.
3．two fifths of the land in that district __is__ (be) covered with trees and grass.
4．nowadays, a large number of women, especially those from the countryside, __work__(work) in the clothing industry.
5．with more forests being destroyed, huge quantities of good earth __are_being_washed__ (wash) away each year.
6．he is the only one of the students who __has_been__ (be) the winner of scholarship for three years.
7．every possible means __has_been_used__ (use)to prevent the air pollution, but the sky is still not clear.
8．when and where to go for the on－salary holiday__has_not_been_decided__(not, decide) yet.
9．she has set a new record, that is, the sales of her latest book __have_reached__ (reach) 50 million.
10．professor smith, along with his assistants，__is_working__(work) on the project day and night to meet the deadline.
1．__only__by working hard can you catch up with the other students in your class.
2．not until he went through real hardship __did__ he realize the love we have for our families is important.
答案与解析：句意：直到经历了真正的困难，他才意识到我们热爱家人的重要性。not until ...置于句首，主句需要部分倒装，用did。
3．at no time __did__ they actually break the rules of the game. it was unfair to punish them.
答案与解析：句意：实际上他们从来不违反比赛规定，惩罚他们不公平。题干中表示否定意义的at no time置于句首，句子应该部分倒装。
4．“never for a second，” the boy says，“__did__ i doubt that my father would come to my rescue.”
5．not once __did__ it occur to michael that he could one day become a top student in his class.
6．__only__when he apologizes for his rudeness will i speak to him again.
7．it was only after he had read the papers __that__ mr. gross realized the task before him was extremely difficult to complete.
答案与解析：句意：直到阅读了这些文件之后，格罗斯先生才意识到摆在他面前的任务是极难完成的。it is/was ... that ...是强调句型。还原为普通句式为：mr. gross realized the task before him was extremely difficult to complete only after he had read the papers.
8．it was not until near the end of the letter __that__ she mentioned her own plan.
答案与解析：句意：直到在书信快结束的时候她才提到她自己的计划。本题考查not ... until ...的强调句形式，即it is/was not until ... that ...。
9．it was with the help of the local guide __that__ the mountain climber was rescued.
答案与解析：句意：正是在当地导游的帮助下这个登山者才被营救了。被强调部分为with the help of the local guide，将本句还原为普通句式为with the help of the local guide, the mountain climber was rescued.判断强调句型的方法：把it is/was和that去掉后剩余的部分仍是一个完整的句子。
10．it was not until i came here __that__ i realized this place was famous for not only its beauty but also its weather.
答案与解析：句意：直到来到这里我才意识到这里之所以出名不仅是因为它的美丽还因为它的天气。强调句结构为it was not until ... that ... “直到……才……”。
11．little __does__ she care what she looks like; all she cares about is her job performance.
12．only after mary read her composition the second time __did__ she notice the spelling mistake.
13．only when he reached the teahouse __did__ he realize it was the same place he'd been in last year.
14．find ways to praise your children often，__and__ you'll find they will open their hearts to you.
15．was it on a lonely island __that__ he was saved one month after the boat went down?
答案与解析：句意：他是不是在船沉了一个月之后在一个孤岛上被人救出来的？结合句意可知，这里用it was ... that强调句结构，被强调的是地点状语on a lonely island。
there __1. was__ (be) a girl named cinderella whose stepmother had two ugly and lazy daughters. not only __2. did__ they get good cares, but also they needed to do nothing. however, __3. only__ by doing dirty housework could cinderella get access to food; and seldom could she __4. gain__ (gain) some rest. not __5. until__ midnight was she allowed to go to bed. poor __6. as/though__ she was, she was very beautiful. one day, from the palace came __7. an__ invitation, saying that the prince would choose his wife. away went her stepmother and her stepsisters to the palace. never had cinderella __8. been__ (be) permitted to go with them.“__9. were__(be) i a princess, i would live a whole new life！” sighed cinderella. no sooner had she sat down __10. than__ a goddess appeared and gave her a smart dress, a cargo as well as horses. but she warned cinderella that everything would disappear at 12 o'clock. when cinderella arrived at the party, __11. so__ attractive was cinderella that the prince only danced with her. hardly had the clock stricken twelve __12. when__ cinderella began to run, and she left a crystal slipper on the stair. the prince's servant came to cinderella's to find out the owner of the slipper. cinderella's elder sister couldn't wear it. __13. neither/nor__ could another sister. not a word could anybody say when cinderella wore the slipper perfectly. from then on she lived happily ever after with her prince.
1．因there be句型为完全倒装，主语为a girl，故谓语动词是was。
2．因not only，..but(also)．..连接两个并列分句，not only放在句首，其后分句需要部分倒装：从前后语境看，get该用一般过去时，而get是原形，故前面应加助动词did。
3．从could cinderella get这一部分倒装可以推断，前面是“only＋状语(介词短语)”。
7．作地点状语的介词短语from the palace提前，句子用完全倒装，invitation(请柬)作主语，前面用不定冠词。
9．此处的were i．..(＝if i were...)表示与现在事实相反的假设。
our school library, along with many other buildings, is very different from other schools'. there __1. are__ (be) two computer rooms, three art rooms, a meeting room and a reading room in the library building. the number of the books __2. is__ (be) large, and maybe there are 100,000 books in it. it is said that all the books cost our school 200,000 dollars. maybe 200,000 dollars __3. is__ (be) large to every student. in the era of knowledge explosion, the number of the students who __4. have__ (have) a thirst for knowledge is increasing day by day. nowadays, our library has been developed into a multifunctional building. there are 50 computers in it. many a student __5. likes__ (like) to surf the internet at weekends here and now you can see that my classmates, mike and john __6. are_playing__ (play) computer games there. when you turn to another room, you will find that a professor and writer __7. is_delivering__ (deliver) a speech. each boy and each girl __8. is_focusing__(focus)on his interesting speech. every time there is a wonderful speech, the audience always __9. cheer/cheers__(cheer) up. you are entering our art exhibition. a teacher with his students is at the room. on the wall __10. are__(be) 100 pictures, which attract many students. an expert and teacher is explaining something important to us.
2．主语是the number of＋名词的复数时，谓语动词用单数形式。
7．当and连接的两个名词是指同一人时，谓语动词应该用单数形式。a professor and writer意思是“一名教授兼作家”。