Amy makes fewer mistakes than Frank. She does her homework ________.

You mustn’t stay __________ late every day. It’s bad for your health.[ ]

I don’t make ________ clear when and where the parents’ meeting will be held.

We must try our best to stop pollution ______ a low-carbon(低碳)life.

Pauline has lost her phone. –No. It’s in her bag. I _________ hear it.