.What some teenagers don’t realize is ____ difficult life can be if they get addicted to drugs. 

It’s generally considered unwise to give a child     he or she wants.

..-How do you find Xiamen,Cathy?-It’s beautiful coastal city. I have ____ it for my next holiday.

He was deep in thought with his eyes_____ on the ceiling.

Although ______ for many years, the two old sisters recognized each other at once.