He asked us we saw the lost cat or not.A. thatB. whatC. whichD. whether

问题补充：

He asked us we saw the lost cat or not.

A. that

B. what

C. which

D. whether

答案：

A. that

B. what

C. which

(答案→)D. whether

解析：考查宾语从句。句意：他问我是否看见丢失的汽车。whether … or not是...或... ,是否，固定搭配，that连接宾语从句，不做成分，但是句意不对，what连接宾语从句，在宾语从句中what做主宾表，which连接宾语从句，意思是“哪个”。故选D。