Question

The airplane _____late, for we didn’t see the famous pop singer until 10 pm

1. A.
   must be
2. B.
   will be
3. C.
   would have been
4. D.
   must have been

Answer 1

D
考查虚拟语气。句意：飞机肯定是晚点了，因为我们直到下午十点钟也没有看见这位著名的歌手。“must+have+done”表示对过去事情的肯定推测，译成“一定做过某事”，故选D。