I can't play with you. I have . homework to do.
Nick is ______ busy ______ he has no time to have a meal with his family.
Mrs. Green warned us ______ more water because of the hot weather.
Look at those students. ______ hard-working they are!
Our teacher told us that the sun ______ the earth light.
If you ask him _____, he will be happy to help you.