问题
单项选择题
— Where was your brother at this time last night
— He was writing an e-mail ______ I was watching TV at home.
A. as soon as
B. after
C. until
D. while
答案
参考答案：D
解析：[专家点评] 由问句中的“at this time last night”可知，问的是具体的时间点，while在此作连词，意为“当……时”，表示两个动作同时发生。as soon as意为“一……就”；after意为“在……以后”；until意为“直到……为止，直到……才”。