He is clever and hard-working, so he has reason to succeed in the exam.
He is only too ready to help others, seldom, ______, refusing them when they turn to him.
— How’s your tour around the North Lake? Is it beautiful? — It ______ be, but it is now heavily polluted.
The house could fall down soon if no one ______ some quick repair work.
Right now you can pay ______ you had to several years ago for a cool computer.
The magazine is a(n) ______ number. You can take it out of the reading room.