— You should go over your test paper ________ you hand it in.— OK, Mr. Wang.
Can you see 11-year-old boy and one-year-old cow in the field?
Lots of students are_________ in tigers and other wildlife.
Why does Liu Tao look all day long?
Our English teacher often asks us_________ English _____in class.
I’m sorry I’m late again________ the heavy rain.