问题
选择题
______ the blind wandering through the traffic, motorists would have to step on their brakes at once.
A．Seeing
B．Having seen
C． Seen
D．To have seen
答案
A
题目分析：考查现在分词做状语：句意：看见盲人在车辆中徘徊，汽车驾驶员要立刻踩刹车。因为motorists和see这个动作是主动关系，用现在分词做状语。选A。