1. He kept his head _____ water when he began to learn swimming, but he raised his head now and then
. In our country, it’s a practice that workers have _____ for the Spring Festival.
They are forbidden _____, for they are still middle school students.
We have the most population in the world, most of it _____ farmers.
_____ at the back of the theatre, the girl couldn’t see ZhouJielun clearly.
The direction_____ which the president would go was kept a secret_____ safety concern.