It is no use _________ to persuade him ________ smoking because he has been addicted to it since he wasyoung.
When I went to the lake, my father was__________ fishing.
He is always full of __________ as though he has neverknown tiredness.
At present we have no __________ of life on otherplanets.
This book __________ ten units,__________ three main revision.
—I think arts are more interesting than science ones. —__________. I prefer science subjects.