All the children like the teachers can understand them.A. whatB. whichC. whoD. whose

问题补充：

All the children like the teachers can understand them.

A. what

B. which

C. who

D. whose

答案：

A. what

B. which

(答案→)C. who

D. whose

解析：本题修饰教师teacher是一个定语从句，教师是人，而且关系词作主语，关系词通常用who，故选C。