1） While it may be more convenient to possess a car，it is also expensive and troublesome at times.   
2） Although I do not earn a great deal of money for this job，the pleasure I receive from the work makes it worthwhile.   

13.表示因果或前提关系   

1） Because of(owing to) the pressure（压力）of examinations， many students are left with little or no free time.   
2） Perhaps it’s because few of us know how to accept compliments（赞扬）gracefully.   
3） That is why housework is considered as such a dreary grind（乏味的苦差事）。   
4） The reason for this is that   

14.表示存在的问题   

1）One of the greatest problems facing the 21st century will be what to do with all the rubbish produced in the world.   
2） To travel abroad is a desire shared by many people，but few can afford to do it.   
3） Cheating is now considered to be a major problem in colleges and universities.   
4） Many people find it harder and harder to keep up with the radical changes that characterize our time.   
5） At first thought， the problem seems far too involved （复杂），but it can certainly be solved when seriously dealt with .   

15． There be结构   

四六级无忧  

1） There are other techniques that might help you with you studying.   
2） There is much that we can learn from the Chinese classic works.   
3） There is no sense（道理）in leaving important decisions to inexperienced people.   

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