问题补充:
His father got him a job in a bank but soon it became clear he was not fit for that kind of work.
A. why
B. what
C. whether
D. that
答案:
A. why
B. what
C. whether
(答案→)D. that
解析:that在此处引导一个宾语从句,thathe was not fit for that kind of work 也可以理解成是宾语补足语,补充说明clear的内容,此处的that是不可省略的。