We all know how difficult it is for all of us to eat better, exercise more, and sleep enough________we know we should.
It isn’t so much whether he works hard; the question is whether he works _____.
___ by the beauty of nature, the girl from London decided to spend another two days on the farm.
The last time I _______ Jack, he _______ football with classmates.
—Did you have trouble with your car this morning? — Yes, but I finally managed _______.
—Growing population resulted in growing rubbish. —There is ______that rubbish will become the major threat to human beings in future.