Question

________ she heard from him, but she spent many a sleepless night before she did.

1. A.
   At no time
2. B.
   At first
3. C.
   At last
4. D.
   At an end

Answer 1

C
四个选项的介词短语意思分别为：at no time从不，在任何时候都不；at first起初，开始时；at last终于，最后；at an end结束，终止。句意：她终于得到了他的信，而她是在度过许多不眠之夜以后才收到的。