Peter's jacket looked just the same as Jack's，but it cost （two）as much as Jack's．
I think there will be （little）pollution in the future because of the new law．
It's too hard for me to learn it．Can you show me how （throw）the ball？
They don't like to eat out．They often cook meals by （they） at home．
Russia is holding the （twenty﹣one） FIFA WORLD CUP now．