Question

He is too old to run_____ to catch up with the young boy.

A．fast enough

B．fastly enough

C．enough fast

D．enough quickly

Answer 1

A

考查enough的用法。句意“他太老了以至于不能赶上那个小男孩。”enough修饰形容词、副词时要后置；排除C、D；fast是副词，排除B。故选A。