They said that not all trainees would be suitable for the jobs they were being trained.A.

问题补充：

They said that not all trainees would be suitable for the jobs they were being trained.

A. in which

B. for which

C. in that

D. for that

答案：

A. in which

(答案→)B. for which

C. in that

D. for that

解析：本题考查定语从句。介词后不可接关系词that，根据句意可知他们训练是为了工作，for表示目的。句意：他们说并非所有的培训者都适合他们所培训的工作。