Food safety is important. Rules to stop people from food pollution.
No one helps us, so we will do it all ______ ourselves.
---People, especially teens, think it_______ great fun to surf on________ Internet. --- I agree with you.
-Tom didn’t go to school this morning, did he?-______. Though he had a bad cold.
-All the dresses look nice. I can’t decide _____.-I think the orange on is the best.
-I can’t find the bookstore _____ my father bought the book for me yesterday.