1. Give your key to your neighbor ________ you lock yourself out one day.
A．as long as B．even though C．in case D．as if
2．[2012·北京卷] One learns a language by making mistakes and ________them.
A．corrects B．correct C．to correct D．correcting
3．—Why does the river smell terrible?
—Because large quantities of water ________.
A．have polluted B．is being polluted
C．has been polluted D．have been polluted
4．You are old enough to________your own living.
A．win B. gain C．take D. earn
5．John isn't here today. Who can________him in the game?
A．replace B．take the place C．instead of D．in place of
6．His idea of having weekly family meals together，which seemed difficult at first，has ________ many good changes in their lives.
A．got through B．resulted from C．turned into D．brought about
7．He tried to make it ________ to his parents that he didn't like the job at all.
A．clear B．clean C．obvious D．anxious
8．After numerous experiments, some doctors have made a ________ in the treatment of cancer.
A．breakdown B．breakup C．breakthrough D．breakout
9. His sister left home in 1998, and ________ since.
A．had not been heard of B．has not been heard of
C．had not heard of D．has not heard of
10．The key ________ the problem of traffic jams is to pay the “congestion charge” ________ by the mayor of London.
A．to solving; introducing B．to solve; introducing
C．to solving; introduced D．to solve; introduced
11．There is something we need to________before the meeting begins.
A．clear up B．clear away C．clean up D．clean out
12．You were fortunate enough to escape ________ for drunken driving, but don't drink again.
A．fining B．to fine C．being fined D．to be fined
13．Young children should be ________ to be honest and equal.
A．brought up B．brought out C．brought down D．brought in
14．—Is this a(n) ________ painting by Picasso?
—No. It's only a good copy.
A．staple B．original C．personal D．traditional
15．The old man was taking a walk, ________ by his grandson.
A．supporting B．supported C．being supported D．having supported
The most exciting kind of education is also the most personal. Nothing can exceed the joy of discovering for yourself something that is important to you! It may be an idea or a bit of information you come across accidentally or a sudden understanding, fitting together pieces of information or are the “payoff” in education. A teacher may direct you to learning and even encourage you in it—but no teacher can make the excitement or the joy happen. That's up to you.
A research paper, assigned in a course and perhaps checked at various stages by an instructor, leads you beyond classrooms, beyond the texts for classes and into a process where the joy of discovery and learning can come to you many times. Preparing the research paper is an active and