This country has high hills, _____ tops spread out into green and moist fields _____ great numbers of sheep are fed.
He waited until it was dark ____ nobody could see him clearly.
Now there are many _____ in our company.
We should think of ways to stop the waste from the factory _____ our living environment.
In my opinion, all Mr. White ___ good to his students in his class at present. He is very strict in their study.
___ nice, the food was sold out soon.