问题
选择题
.I was about to leave_________I saw him_______ towards me, with a bag in hand.
A．while; running
B．when; running
C．as; ran
D．when; to run
答案
答案：B
考查固定句型。句意“我正要准备离开时，突然看见他向我跑来，手里拿着一个包。”be about to do sth. when...“正要做某事时，突然发生......”。see sb. doing sth.“看见某人正在做某事”。故选B。