Is _____ necessary to take off our shoes when we enter the computer lab?
We asked the teacher to explain _______.
—Did you see a man in black pass by just now?—No, sir. I ______ a newspaper.
Only by working hard can you ______ the goal.
. —Did you have ________ fun at the party?—Yes. It’s ________ shame that you missed it.
It was in the lab ______ was taken charge of by Pro. Harris ______ they did the experiment.