The best way to explore _______ countryside is on _______foot.
The news about the terrible flood there greatly discouraged __________ there for a sightseeing.
He's unlucky,and he's always suffering____________ luck one after another.
If you ____________ stop smoking, you can only expect to have a bad cough.
__________ , we'll come to see you again.
I think the doctor is able to cure of __________is called a suspect.