One can’t be really happy if _________he enjoys doing is regarded by society as of no importance.
We must notice the use they are the new energy.
Since you have lots of spare time, why not _ a foreign language?
Unfortunately, not everyone has realized the important part that healthy diets in their daily life.
I was on the point of talking to the professor when John .
It is said that he will his business to his son when he retires.