Outdoor activities are as much a part of childhood for this generation of Chinese children as they __________ for their parents and grandparents.
The book didn’t _______ children probably because it employed too many scientific terms.
Speaking of all the songs he has written, I think this is probably his _______ one.
I would appreciate it _______ you call back this afternoon for the doctor’s appointment.
We can never expect _______ bluer sky unless we create _______ less polluted world.
We all know that, _______, the situation will get worse.