Question

My uncle lost his job and was short of money, so _________ his flat and move in with his friend．

1. A.
   that he did was to sell
2. B.
   what he did sell
3. C.
   what he did sold
4. D.
   what he did was to sell

Answer 1

D
从题意知“失业缺钱，他要做的就是卖房子投靠朋友”，what he did作主语从句，不定式to sell his flat and move in with his friend作表语。答案为D。