--Don’t smoke any more, Ralph ! It is very bad for your health ! --I know I should give up smoking, but ________.
---You don’t often see them, do you? ---No, I see ______of them.
He is clever and hard-working, so he has _____ reason to succeed in the exam.
It’s ______, as I trust you so much.
One of the students hasn’t prepared ____ lessons very well.
Either the boy or his sister must have _____ dinner here.