Question

Can you tell me ________ at that time?

A. what were they doing
B. what they were doing
C. what are they doing
D. what they are doing

Answer 1

答案B
考查宾语从句。宾语从句用陈述句语序。排除A、C；at that time指的是过去的时间，故用一般过去时，排除D。句意“你能告诉我那时他们在做什么吗？”故选B。