Question

Sam enjoys ________ stamps. And now he has 226 of them.

1. A.
   to collect
2. B.
   collected
3. C.
   collects
4. D.
   collecting

Answer 1

D
enjoy doing sth意为“喜欢做某事”enjoy后需接动名词短语，而A为不定式，B为过去式，C为第三人称单数形式，故选D项。