--- Betty , welcome to my birthday party . Please make yourself at home .--- ________.
A man does not know the difficulty of anything _____ he does it personally .
---What was the party like ? ---Wonderful . It is years _____ I enjoyed myself so much .
We will take _____ wants to go there for a sight-seeing .
I think the doctor is able to care of _____ is the matter with your son .
_____ in thought , he almost ran into the car in front of him .