5.(单选题,2分)The manager put forward a suggestion ()we should have an assistant.There is too much work to do.

21.(单选题, 2分)Mary found it useful to () a deep breath when she feels nervous.

20.(单选题, 2分)⼀We should()(the time we spend with our family and friends.—Sure. They are the most important people for us in the world.

19.(单选题, 2分)To raise people's()of the monarch butterfly, scientists have been doing researches on this wonderfulcreature.

18.(单选题, 2分)As government officers, we tried to()that everyone got a fair deal.

17.(单选题, 2分)They spent()(money on the new hospital.

16.(单选题, 2分)We can()ourselves because we have already been old enough.

15.(单选题, 2分)The()(of this kind of electric car is not high, and many young people can afford it.

14.(单选题, 2分) Guangzhou()( Flower City.

13.(单选题, 2分)She realised that one of the greatest()()the distance that usually exists between people.

12.(单选题, 2分)Maria cleans her room()to keep it().