—I have worked hard at math, but it seems that I haven’t made any progress. —Keep on _____ at it, and you will be successful. A. work B. working C. to work
—Why didn’t you go to play football with us yesterday afternoon? —I _____my mother with the housework then.
We can easily become unhappy_____ we work out our problems in our daily life.
I’ll never forget the day_____ the great scientist came to our school and gave us a speech.
Last year was a hard time to my friend Jim, but he didn’t_____ hope.
_____you do, don’t miss this exhibition, for it’s so hard for me to get the tickets.