Question

I'm sorry ________ that your bike was lost.

1. A.
   hear
2. B.
   hearing
3. C.
   to hear
4. D.
   heard

Answer 1

C
解析：
这是一个简单句，前面已有be动词的第三人称单数形式is，做谓语，且be sorry to do为固定搭配，故动词hear用不定式形式。