下列各句中,没有语病、句意明确的一句是

A bus is slower than a plane, ____ it doesn’t cost so much.

Is honesty the best policy? We _ that it is when we are little. [ ]

Our school reading room ________ from 8a.m. to 5p.m. every day.

题文 The girl seemed too busy __________ her test _________ her mother enter the room.