Try not to buy too many things from abroad _________ it may cost a lot of money to bring them back.

 — 　　　 times did you do exercise last week?   — Twice.

—I’m afraid that I can’t do it.—Oh, you should believe in yourself. You won’t know what you can do______ you try it.

Teenagers would rather_____ secrets with friends than _____ about them with parents.

In summer, food goes bad easily     the weather is very hot.