—Who teaches ________ English?—Miss Li. She is popular among the students.
As someone ______ the curtain, the famous singer came out. The fans ______ and screamed with excitement.
He managed to become a great inventor ___ he left school at 16.
Yesterday morning I was just leaving_________the telephone rang.
---What’s wrong with you, Dave?---My homework can’t be __________ on time because I’ve left it at home.
We can’t work out the physics problem. Can you tell us ____?