Food safety is important. Rules to stop people from food pollution.
A student need a ________ place to study, but , in fact, some parents are always watching TV at that time.
When the first settlers came to North America, they had to ________ the forest and found a way out.
—I'd like to go camping with you, but I have meeting _______.—If you don't go, ______.
—Why are the lights in the teachers’ office still on?—There ________ be some teachers working there.
—What are people supposed to do when they meet for the first time in China?—They are supposed to _______.