A:Seeing a boy lying on the road
B:On seeing a boy sitting on the road
C:The minute the driver saw a boy seated on the road
D:The driver had seen a boy standing on the road
2016年4月14日晚至15日凌晨日本九州熊本县发生多次最大震级达到里氏6.5级的强烈地震,地震导致近千人受伤,数十人死亡.据此回答6﹣7题.