Question

We often hear her ________ in the next room.

1. A.
   to sing
2. B.
   sings
3. C.
   sing
4. D.
   sang

Answer 1

C
hear sb do sth或 hear sb doing sth表示听见某人做某事或听到某人正在做某事，do sth或 doing sth做 sb的宾语补足语。除hear外，还有see，notice，smell等词也可接动词原形或现在分词，作宾语补足语。