The reason he wants to take a leave of absence is _______.

The reason he wants to take a leave of absence is _______.
A、because he is needing a complete rest
B、because he needed a complete rest
C、that he needs a complete rest
D、because a complete rest is needed by him
【正确答案】：C
【题目解析】：that引导表语从句，because只能引导原因状语从句，故排除选项A，B和D。