We’d better clean out the room this week.

我们这周最好把房间打扫干净。

You may use the room as you like so long as you clean it up afterwards.

你喜欢的话可以使用这个房间，只是要在用完后打扫干净。

I need to change and clean up.

我需要换洗一下。

It may now be too late to clean up the river after such heavy pollution.

这条河遭到如此严重的污染，现在净化它可能太迟了。