—Life is limited. We had better _______ it on valuable things.—Good idea. And we should spend more time ______ our family members.

---_____ will you be in Guangzhou? ---I am going to leave for Beijing in two months’ time.

At the top of the high mountains, there is very _____ oxygen in the air.

 ---- Could you tell me how to write an application letter?  ---- With pleasure. Remember that the letter should be written in the formal _______.

—John is a hardworking student．---You’re fight．He         play computer games，but he doesn’t do it now．