Question

Linda , there's somebody knocking at the door．Go and see who ________ is．

1. A.
   he
2. B.
   she
3. C.
   it
4. D.
   that

Answer 1

C
解题指导：he明确指男性；she明确指女性；it通常指物，当指人时，表示不知对方是谁，性别不明确；that确指那个人或物。