There are two main causes of cancer: heredity and environment. We can do nothing to change our heredity, that is, the basic physical characteristics that were passed on to us by our parents. However, we can do a GREat deal to control our environment, which may account for 80-90 %of all cancers.
Environmental pollution can be divided into two kinds: personal and impersonal. Personal pollution may be defined roughly as unhealthy habits such as smoking, drinking, and eating the wrong foods. Clearly, with enough will power we can control this personal environment.
Impersonal pollution, on the other hand, refers to those things which are beyond our individual control. One example would be industrial pollution, which is very hard to control because of the expense involved. It would be expensive in terms of profits and perhaps jobs. The American automobile industry, for example, resisted the law requiring smog-control devices because it feared the added expense would reduce profits. Nevertheless, some laws protecting the environment have been quite successful in reducing pollution.
2012职称英语考试综合类完形填空考前冲刺(10)
2012职称英语考试综合类完形填空考前冲刺(6)
2012职称英语考试综合类完形填空考前冲刺(3)
2012职称英语考试综合类完形填空考前冲刺(4)
2013年职称英语考试综合类完形填空练习(4)
2012职称英语考试综合类完形填空考前冲刺(7)
2013职称英语完形填空强化练习题及答案(26)
2013年职称英语考试综合类A级-完形填空(2)
2013职称英语完形填空强化练习题及答案(28)
2013年职称英语综合类A级完形填空练习题(2)
2013年职称英语考试综合类完形填空练习(11)
2013职称英语完形填空强化练习题及答案(6)
2013职称英语完形填空强化练习题及答案(1)
2013年职称英语考试综合类完形填空练习(6)
2013职称英语完形填空强化练习题及答案(4)
2013年职称英语考试综合类完形填空练习(3)
2015年职称英语考试理工类完形填空测试题(3)
2013年职称英语考试综合类A级-完形填空(4)
2013年职称英语综合类完形填空练习题(1)
2012年职称英语综合类A级真题及答案(完型填空)
2012职称英语理工类B级完形填空模拟试题(2)
2013职称英语完形填空强化练习题及答案(3)
2013年职称英语综合类A级完形填空练习题(1)
2012年职称英语综合类B级真题答案(完型填空)
2013职称英语完形填空强化练习题及答案(9)
2013年职称英语考试综合类完形填空练习(5)
2013年职称英语综合类A级完形填空练习题(3)
2013年职称英语考试综合类A级-完形填空(1)
2013职称英语完形填空强化练习题及答案(13)
2013职称英语完形填空强化练习题及答案(11)
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |