Question

Walking around, I found the city was full of people ________ for the festival．

1. A.
   wearing
2. B.
   had new clothes on
3. C.
   dressing up
4. D.
   dressed up

Answer 1

D
从句子意思来看，空格处连同它的后面应该是作定语用来修饰前面的名词people，而dress up的意思是“打扮，装扮”，符合句子意思，它和people的关系应该是被动，所以该选过去分词来作定语。