Question

Simon couldn't come to the party, ________ was a pity．

1. A.
   which
2. B.
   that
3. C.
   it
4. D.
   what

Answer 1

A
因为此句为非限制性定语从句，而此句所修饰的不是前面某一个词，而是代表整个主句内容，通常用逗号与主句分开，所以正确答案是A。