1．The key to ________(solve) the problem is to meet the demand made by the customers.
[答案] solving
2．She earns her living ________ selling insurance.
[答案] by
3．Suzhou, which is the place I want to visit this summer, is known ________ its beautiful gardens.
[答案] for
4．No one can escape ________(punish) if he breaks the law.
[答案] punishment/being punished
5．You may be ________(physical) and mentally exhausted after a long flight.
[答案] physically
