Oh, it ________so nice. What beautiful music it is !
I don’t know _____ he will come or not. _____he comes, I’ll tell you.
We ___ use mobile phones when the plane takes off.
He told us where tomorrow morning.
—Excuse me, where is the nearest bus stop?— ____________.
The left-behind kids(留守儿童)can’t see their parents____ the parents come back home from work.