Question

【题目】 Vitamin B could help lessen the effects of the most dangerous type of air pollution，according to a new study published recently. In the first study of its kind，a team of international researchers looked at the damage caused by one of the pollutants that has the most severe impact on health: PM2.5.

Particulate matter，or PM，is a type of air pollutant consisting of small particles of different sizes. PM2.5 has a diameter of fewer than 2.5 micrometers，about 30 times smaller than a human hair. These particles are so small that they can go into our respiratory system (呼吸系统), resulting in lung and systemic inflammation (炎症) and stress.

The team found that something as simple as a daily vitamin B supplement could potentially reduce the impact of the tiny particles on the human body，although they stressed that the research was in its early stages and the sample size was small.

For this study，10 volunteers were initially exposed to clean air and given a placebo (安慰剂) to check their responses. The group then took another placebo for four weeks before being exposed to heavily polluted air from downtown Toronto，where an estimated 1，000 cars pass every hour. The bad air was delivered to the volunteers through an “oxygen－type” face mask. The experiment was then repeated，with each volunteer taking a vitamin B supplement daily made up of 2.5 mg of folic acid，50 mg of vitamin B6，and 1 mg of vitamin B12. B6 can be found in liver，chicken and nuts，and B12 in fish，meat，eggs，milk and some cereals.

The researchers found that four weeks of vitamin B supplements reduced the damage of PM2.5 exposure by 28%－76%. The results highlight how prevention at an individual level could be used to fight the harmful effects of PM2.5.

【1】Why is PM2.5 harmful to our health?

A.It pollutes and poisons the air.B.It is too much to be got rid of.

C.It carries viruses and diseases.D.It is easily breathed in and damages our body.

【2】What can we infer from Paragraph 3?

A.The process of the research was not scientific.

B.This kind of research has been done many times.

C.Further studies are needed to confirm their findings.

D.Vitamin B is hard to obtain in people’s daily life.

【3】What is the text mainly about?

A.International researchers have a new finding.

B.Vitamin B could reduce the damage of PM2.5.

C.Particulate matter does great harm to our health.

D.Emission control and regulation are badly needed.

【4】The new study was probably published ________.

A.in a science journalB.on a government website

C.in a fashion magazineD.in a medical textbook

Answer 1

【答案】

【1】D

【2】C

【3】B

【4】A

【解析】

本文是一篇说明文。文章提到吸入人体内的PM2.5会导致疾病。不过，研究发现维生素B在一定程度上能降低PM2.5的危害。

【1】

细节理解题。根据第二段中的These particles are so small that they can go into our respiratory system，resulting in lung and systemic inflammation and stress（这些颗粒非常小，它们可以进入我们的呼吸系统，导致肺部和全身的炎症和压力）可知，PM2.5 (细颗粒物)很小，能进入我们的呼吸系统，导致肺部和全身炎症。故选D项。

【2】

推理判断题 。根据第三段中的although they stressed that the research was in its early stages and the sample size was small（尽管他们强调研究还处于早期阶段，样本量也较小）可知，该项研究处于初级阶段且样本规模小，因此还需要更多的研究来证明研究团队的发现。故选C项。

【3】

主旨大意题。首先作者在文章第一段第一行提到Vitamin B could help lessen the effects of the most dangerous type of air pollution（维生素B可以帮助减轻最危险的空气污染的影响），接着文章的文章第一段剩余部分和第二段谈到PM2.5的定义以及PM2.5的危害。从文章的第三段到第五段作者通过研究的过程和数据告诉我们维生素B能降低PM2.5的危害。综合分析，这篇文章主要再讲维生素B能降低PM2.5的危害。故选B项。

【4】

推理判断题。根据文章第一段Vitamin B could help lessen the effects of the most dangerous type of air pollution，according to a new study published recently（根据最近发表的一项新研究，维生素B可以帮助减轻最危险的空气污染的影响）可知，后面段落的内容都是用来描述这个已公布新研究的一些细节。因此可以判断该文很可能出自科学期刊。故选A项。