—Excuse me, Maria. Can I use your bike?—Sure. Here you are. But you must return it _____ time.
I believe that he _____ us as soon as he comes back to China.
The boy has poor eyesight because of _______ computer games.
Every time when something ____ me, I turn on the radio and listen to music.
Tom is a true friend, _____ I didn’t like him at the _____.
Our Math teacher often gives us __________ on how to learn Math.