Tom has difficulty Chinese, so he often asks me advice.

－You should pay attention to the traffic light ______ you cross the street.－Sorry, I will be careful next time.

Listen! Is it Linda singing in the next room –No, it __________ be her. She is still in Shanghai.

In the last twenty years, seven Canadian scientists _____ the Nobel prize!

Mrs Baker has her hair _____every Fridayafternoon after work.