1．Some parents complained(抱怨) that their children are busy with heavy homework.
2．She hasn’t been seen for days and we are concerned(担心) for her safety.
3．An unhappy home environment(环境) can affect a child’s behavior.
4．The shady trees provide protection(保护) against the burning rays of the sun.
5．We should pay more attention to the pollution of the atmosphere(大气)．
6．The major(主要的) problem we face is that we have no money now.
7．There wasn’t enough evidence(证据) to prove him guilty.
8．We have a(n) urgent(紧急的) need for help. We are running out of food.
