It’s our duty ________our city clean and beautiful.—Yes. We should do something for it.

Believe it or not, I passed the driving test at the first attempt yesterday— Great! But remember you can never be ___ careful when driving a car in the street

Are you _______ to go hiking with us— Yes, I _______.

“_________ necessary to pay attention to _________ to teachers in class .” My dad said.

_____ you please play tennis with me —Sorry, I _____.