----- What can we do during the vacation? ------ ________ about going to the beach?

—_________ a week does Tom go to the club ? — Once a week.

Do you go to school on foot    ？

--- I don’t think the film named　“Hero(英雄)”　is very exciting.  --- I don’t think it is，____________. 

-- Is air the lightest thing in the world?-- Not            . Scientists from Zhejiang University have just developed the world’s lightest material.