Question

Mr Li required the computer equipment referred ________ used in every classroom.

1. A.
   should be
2. B.
   have to be
3. C.
   to be
4. D.
   to being

Answer 1

C
因为在表示“要求”的require, request, ask, demand等动词后的宾语从句的谓语要用“(should+)动词原形”，句中referred to是过去分词短语，作the computer equipment的定语，所以选C。