Can I join your club,dad? ——You can when you______a bit older

Four other students aren’t in the classroom ____ Lin Tao.Where are they ?

I’d like to travel by air _________ it usually costs a lot of money.

Nowadays people seem to be becoming more and moreselfish— How much better life would be if we ______ to thevalues of the past!

Google launched its Body Browser, an application that allows people to _____ the human body.