If you want to be a ______, you should study math hard.
Oh, my god! Our house __________last night. Look at the footprints (脚印) on the floor.
— Why is your bedroom so dirty?— Sorry, Mum. It ___________. I felt very tired after playing soccer.
Tom said he had never been there, but he was .
— Michael Jackson was called the king of pop, wasn’t he? — Of course. He by people all over the world.
—It's difficult to get to the other side of the river.—I think a bridge ________ over the river.