课时作业(十七) [必修4 Unit 2 Working the land]
(限时：35分钟)
Ⅰ.单项填空
1．It's not easy to learn English well.________as much as possible is necessary.
A．Having read B．Read
C．Reading D．To have read
2．—I regret________you that John has been fired.
—I can hardly believe my ears.He is such a fine worker.
A．telling B．having told
C．to tell D．to have told
3．—The cars give off a great deal of waste gas in the streets.
—Yes.But I'm sure something will be done to________air pollution.
A．reduce B．remove
C．drop D．warn
