—Did they have fun _______ the summer Palace ? —Yes. They really enjoyed themselves there.
—Jack, your hair is too long! —Really? I’ll have it _____ right now.
My parents like the music ____ is quiet and gentle.
We often see Betty ____ the old man with his housework.
In our city, _____ middle school students want to work as a teacher in the future.
I found _____ necessary to save energy and protect the environment.