He has to_________ 20 yuan on the book. But I needn’t _______ any money for it.

Betty and Lingling are _____ the classroom. [ ]

There were lots of people _________ the bus on my way back home yesterday.[ ]

Nowadays, children under 1.4 meters _______________ be free to take buses in some cities.

Don’t copy others’ work. If you do it by ________, you’ll feel much better.