Question

---Laura, we've decided ________ on a trip this afternoon. Will you join us?

---I'm afraid not. I have a composition ________.

1. A.
   to go; to write
2. B.
   to go; writing
3. C.
   going; to write
4. D.
   going; writing

Answer 1

A
decide后面接动词时要用动词不定式，由此排除C、D；结合“I'm afraid not（恐怕我今天下午我不能旅行）”可知“我有一篇作文要写”，故应用动词不定式作定语修饰composition。因此选A。