________ the earth to be flat, many feared that Columbus would fall off the edge of the earth.

 — What do you think of the book? — Oh, excellent. It is worth __________ second time.

____________for children, the album became popular with Parents __________it came out.

----What’s it that cost him the job?----_______ experience .He was always very nervous.

It was _____ computer games that cost the boy a lot of time that he ought to have spent on his lessons.