The man on the bike travelled( )fast( )hit a boy

B and 连接两个动作.travelled and hit
不能选A.因为
The boy on the bike travelled so fast that he hit a boy.so+形容词/副词+ that -从句（ 如此.以至于.)
骑自行车的那人骑得太快了,以至于他撞到了一个男孩.