He must be helping the old man to water the flowers, ______?
If you hurry up, I think it quite ____for you to catch the flight, for there are still 50 minutes left.
Nowadays people are convinced ___ the negative effect of second-hand smoking ___ people around.
—Would you rather ______ there to attend the lecture tomorrow? —No, I’d rather he ______ there instead of me.
It is hard for us to eat better, exercise more, and sleep enough, ________ we know we should.
At the conference, they came up with three different _____ to solving the serious problem.