t comes to my preference for entertainment in the spare time, I prefer gardening to parachuting, because the latter is a dangerous _____.

You should ________ your son. He works harder than before.—Thanks, I will.

Will you please ____ so much noise, Dongdong—Sorry. I won’t.

My friend, Tom, may have missed taking the flight to Africa, ______ he can’t arrive for another hour.

Don’ t worry. A number of efforts are being made ______ the whole system operating normally.