问题补充:
Can you tell me when I called you?
A. what were you doing
B. what are you doing
C. what you were doing
D. what you are doing
答案:
A. what were you doing
B. what are you doing
(答案→)C. what you were doing
D. what you are doing
解析:英语宾语从句中一般为陈述语序。联系下文,当我打电话给你时,可知宾语从句中描述的是过去某时正在发生的动作,用过去进行时态。故选C。