我们应该在扔掉废物前进行分类.
We should divide the waste into different groups before it .
We will hold a party to say goodbye to our teachers next (星期三).
Every time I want to give up, my parents always (鼓励)me to keep trying.
The cinema was half (空的) because the movie was so boring.
Bob and Jim have been good friends (自从) they joined the same tennis team.
The singer is good at playing the (吉他) and making wonderful music.