Not until I began to work ______ how much time I had wasted.
We have every reason to believe that 2008 Beijing Olympic Games will besuccess.
He has worked the maths problem for nearly an hour but he simply can’t work it. On ;atB. on ;out C. at ;up D. for ;out
Every means ______ tried but without much result.
______ is to attend our evening.
If you keep __________ English, you can learn English well.