Jack is a great talker. It's high time that he ________ something instead of just talking.
---How do you like your new assistant? ---To tell you the truth,I've found the girl _____.
---Couldn't you leave a message for him? ---Yes,but I need something ______I can write a note.
---So you've left the classroom key inside again? ---No.I've got it with me this time,but I have forgotten ______ the door?
The number of smokers in the countryside is usually greater than _______ in cities.
Most of us see a doctor ______ when we get a cold or something.This won't cost us a lot.