Question

---This physics problem is too difficult. Can you show me ________, Wang Lin?

---Sure.

1. A.
   what to work it out
2. B.
   what to work out it
3. C.
   how to work it out
4. D.
   how to work out it

Answer 1

C
show sb. sth.意为给某人演示什么由句意可知，空缺处须填表方式的从句，work out意为“解答”，代词需放中间。