问题
选择题
Mr Li required the computer equipment referred ________ used in every classroom.
A．should be
B．have to be
C．to be
D．to being
答案
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。