Ms.Wang is very strict with us. She always asks us to do everything according to her i .
Who is (敲)at the door?
Maybe it's the postman.
I can't hear you (清楚地). Please speak a little bit louder.
I met a friend of (她的)in the street yesterday.
Drinking too much juice can be (有害的) to people's teeth.
The use of new energy cars helps to reduce air (污染).