Great changes __ in the city in the past 20 years, and a lot of factories ____.
I don’t know ______ with this problem. It’s too hard.
The notebook ___________ be John's .There is his name on it.
_____you go, ____you do in your school, You must obey the rules.
Tony didn't run ________.He was behind all the other runners.
He used to like playing________ piano,but now he likes playing _________ basketball.