— Has Mary finished writing her article?— No, and it _____ before class was over.
Is _____ necessary to take off our shoes when we enter the computer lab?
____ matters most in learning English is enough practice.
Only when in the afternoon able to leave.
There are 51 students in Class Three, _____ failed in the test.
______ happened to be no one in that house when the typhoon hit the area.