英语六级段落匹配专项练习题
10. What we can learn from "Paper from Rag" is that you had better buy archival materials from specialist suppliers.
练习题三答案：
文章精要
本文主要介绍了我们平常所见所用的纸的复杂性，通过介绍用木头和破布料造纸的过程，使我们对纸的类别、属性有了更深入的了解。
1.B
根据题干中的信息提示词corn—flake packet,high grade card,可定位到文章第二段，该部分最后提到corn-flake packet在制造过程中比高等级的纸(high grade card)便宜.
2.C
根据题干中的信息提示词soft wood，cotton and rags，可定位到文章第三段最后一句。
3.D
根据题干中的信息提示词final product，可将答案定位到D段，第二、三句提到最后的产品来源于纤维素纸浆。
4.D
根据题干中的信息提示词white paper and card，可将答案定位到D段，该部分最后提到为了得到白纸，纸张生产者在制造过程中添加了其他化学物质。
5.E
根据题干中的信息提示词essential for the tree，可将答案定位到E段，该部分提到木质素是木头的主要组成物，其作用是凝聚纤维素，但它会使纸张变得易碎。
6.F
根据题干中的信息提示词lignin，可将答案定位到F段，该部分最后提到许多纸张生产者在生产过程中会保留木质素，主要是因为它会增加树木的造纸产量。
7.G
根据题干中的信息提示词acid，可将答案定位到G段，该部分最后提到酸对相纸的原料尤其不利。
8.F
根据题干中的信息提示词lignin和paper可定位到文章的F段，因为该段提到，如果在纸张的生产中去除木质素，将会降低树木出产纸张的量，由此可以知道，去除了木质素的纸张价格必定会更加昂贵。
9.K
根据题干中的信息提示词cotton and rag waste可定位到文章的K段，该部分告诉我们，尽管用棉花和破布料造的纸里没有木质素，但它们要比木制的纸贵很多，这是因为棉花和破布料的数量比树木少得多，由此可以得出答案。
10.M
根据题干中的信息提示词Paper from Ra9可定位到文章的最后一段，该部分提出最好到专业的供应商那里去买档案材料，由此可以得出答案。
练习题四
Definitions of Obesity
A: How does one define when a person is considered to be obese and not just somewhat overweight? Height-weight tables give an approximate guideline as to whether one is simply overweight or has passed into the obese stage.
B: The World Health Organization recommends using a formula that takes into account a person's height and weight. The "Body Mass Index" (BMI) is calculated by dividing the person's weight in kilograms by the square of their height in meters, and is thus given in units of kg/m2. A BMI of 18.5-24.9 is considered to be the healthiest. A BMI of between 25 and 29.9 is considered to be overweight, while a BMI of over 30 is considered to be obese.
C: However, it is recognized that this definition is limited as it does not take into account such variables as age, gender and ethnic origin, the latter being important as different ethnic groups have very different fat distributions. Another shortcoming is that it is not applicable to certain very muscular people such as athletes and bodybuilders, who can also have artificially high BMIs. Agencies such as the National Cholesterol Education Program (NCEP) in the USA and the International Diabetes Foundation (IDF) are starting to define obesity in adults simply in terms of waist circumference.
Health Effects of Obesity
D: Over 2000 years ago, the Greek physician Hippocrates wrote that "persons who are naturally very fat are apt to die earlier than those who are slender". This observation remains very true today. Obesity has a major impact on a person's physical, social and emotional well-being. It increases the risk of developing diabetes mellitus type 2 ("mature onset diabetes") and also makes Type 2 diabetes more difficult to control. Thus weight loss improves the levels of blood glucose and blood fats, and reduces blood pressure. The association between obesity and coronary heart disease is also well-known.
Cancer
E: Furthermore, in 2001 medical researchers established a link between being overweight and certain forms of cancer, and estimated that nearly 10,000 Britons per year develop cancer as a result of being overweight. This figure was made up of 5,893 women and 3,220 men, with the strongest associations being with breast and colon cancers. However, it is thought that being overweight may also increase the risk of cancer in the reproductive organs for women and in the prostate gland for men.
F: The link between breast cancer and nutritional status is thought to be due to the steroid hormones oestrogen and progesterone, which are produced by the ovaries, and govern a woman's menstrual cycle. Researchers have found that the more a woman eats, or the more sedentary her lifestyle, the higher are the concentrations of progesterone. This link could explain why women from less affluent countries have lower rates of breast cancer. Women from less affluent nations tend to eat less food and to lead lifestyles which involve more daily movement. This lowers their progesterone level, resulting in lower predisposition to breast cancer.