17.—Is there any better way to help my son get rid of the habit of playing computer games? —To tell you the truth, it’s very hard. But we_______on this problem to improve the situation.
______ more and more trees cut down, many animals and insects are dying out.
Could it be in the place ______ we visited yesterday ______ you left your book?
Although the number of competitors ___ limited, a number of our classmates ___ eager to take part in it.
We don’t need to do ___ extra work this evening. The day’s work was almost at ____ end now.
He talks about Rome as if he _________there before.