问题
选择题
I the office yesterday afternoon when a stranger came in with a boy．
A．left
B．was about to leave
C．was to have left
D．will leave
答案
答案：B
这题考查词组：be about to do …when…“刚要做…这时”，句意是：昨天下午我刚要离开办公室这时一个陌生人带着个孩子进来了。选B。
