Beijing, the capital of China, is one of _________ cities in the world.

下列各句中，没有语病的一句是（ ）

The prisoners became________in their attempts to escape. [ ]

You needn’t get up early, we have changed our plan.— Really, but I _______ about it.

Mum, would you please buy me an MP5 player? — If you can help do some housework the whole vacation, you ____ have one as a reward.