---What is that? Is it an English learning machine?---Yes. It ________ us to improve our English.A. is used for helping B. used to help C. used to helping
---Did you enjoy yourself at the concert? ---Yes, I’ve never been to ________ one before.
---Do you know __________? ---I’m not sure. Maybe he is a teacher.
It’s said ________ a little child does ________ much homework every day.
---My uncle goes to climb the Yellow Mountain every year. ---Oh, really? He ________ climbing mountains.
My sister ______ go to bed _______ my mother came back last night.