You can’t be ______ when you camp _____ a high altitude, ________ the air is thin. 

He is a           boy.

There are several         plans here. Which one do you like best?

There is an old proverb,“Love me,love my dog.”But there is______wisdom in 35. There is an old proverb,“Love me,love my dog.”But there is______wisdom in this:“Love me,love my book.”

----The government claims to exercise control over housing prices. But the fact is_______ ideal.---- It’s _______ wonder that there are constant complaints on the Internet.