Question

Perhaps I can't come back________eight o'clock．Don't wait for me for supper．

1. A.
   after
2. B.
   until
3. C.
   at
4. D.
   for

Answer 1

B
分析：就單句來說after eight o'clock，until eight o'clock，at eight o'clock都是對(duì)的，但聯(lián)系第二句就必須考慮晚飯的時(shí)間，晚飯不可能是在八點(diǎn)鐘，因此只有用until才是正確的。Perhaps I can't come back until eight o'clock．句意是“可能我要到八點(diǎn)鐘才能回來。”(延伸)1)使用until要注意是肯定句還是否定句。使用肯定句時(shí)表示“動(dòng)作一直做到until所表明的時(shí)間，到了這時(shí)間，原來在做的動(dòng)作要停止不做”，因此在肯定句里，必須是持續(xù)性的；而在否定句里，意思是“動(dòng)作一直不發(fā)生，到了until所表明的時(shí)間時(shí)，原來不做的動(dòng)作要發(fā)生”。因此如果是短暫性的動(dòng)詞，只能出現(xiàn)在含有until的否定句里。錯(cuò)：Perhaps I will come back until eight o'clock．對(duì)：Perhaps I won't come back until eiight o'clock．2)此處until后面跟的是名詞，屬于介詞用法，until也可以引出時(shí)間狀語從句，屬于連詞用法，但肯定句和否定句的用法是和作為介詞時(shí)的用法是相同的。Don't leave here until I come back．(＝Wait here until I come back．)