Question

【题目】Particulate Matter

There are things floating around in the air. Most of them, you can not even see. They are a kind of air pollution called particles or particulate matter. In fact, particulate matter may be the air pollutant that most commonly affects people’s health.

Have a Look.

Particles can come in almost any shape or size, and can be solid particles or liquid droplets.【1】 These two groups differ in many ways. One of the differences is size, we call the bigger particles PM 10 and we call the smaller particles PM 2.5.

BIG.

The big particles are between 2.5 and 10 micrometers (from about 25 to 100 times thinner than a human hair). These particles are called PM 10 (we say ―PM ten, which stands for Particulate Matter up to 10 micrometers in size).【2】

SMALL.

The small particles are smaller than 2.5 micrometers (100 times thinner than a human hair).【3】We say ―PM two point five, as in Particulate Matter up to 2.5 micrometers in size.The smaller particles are lighter and they stay in the air longer and travel farther. PM 10 particles can stay in the air for minutes or hours while PM 2.5 particles can stay in the air for days or weeks.And travel? 【4】 PM 2.5 particles go even farther; many hundreds of miles.

Particulate Matter and Your Health.

When you breathe, you take in the air along with any particles in the air, like heavy metal sand cancer causing organic compounds. Both PM 10 and PM 2.5 particles can cause health problems, specifically respiratory (呼吸的) health.【5】 Exposure to particulate matter leads to increased use of medication and more visits to the doctor or emergency room.

A.These particles are called PM 2.5.

B.We divide particles into two major groups.

C.These particles cause less severe health effects.

D.PM 10 particles can travel as much as 30 miles.

E.Air pollution is a growing problem in the whole world.

F.PM 2.5 can have worse health effects than the bigger PM 10.

G.Air pollutants have great effects on our environment and our health.

Answer 1

【答案】

【1】B

【2】C

【3】A

【4】D

【5】F

【解析】

本文为说明文。大气中有很多悬浮颗粒物，从大小上可以分为PM 10和PM 2.5，它们不但造成大气污染，而且还影响人们的身体健康。文章主要对颗粒物的分类及特点进行了介绍。

【1】考查对上下文的理解及推理判断能力。空格后面“These two groups differ in many ways. One of the differences is size, we call the bigger particles PM 10 and we call the smaller particles PM 2.5.”这两个群体在许多方面都不同。其中一个区别是大小，我们称较大的颗粒为pm10，称较小的颗粒为pm2.5。可知，我们可以把这些颗粒分为the bigger和the smaller两类。分析选项可知B项 We divide particles into two major groups（我们把粒子分成两大类）意义一致，而且有词（two groups）复现，故选B。

【2】考查对上下文的理解及推理判断能力。空格前提到了PM 10的相关知识，后面理所当然应提到它对人类健康的影响，且在第一段就已经提到了颗粒物会对人类的健康造成影响，所以答案C项These particles cause less severe health effects（这些微粒对健康的影响较小）符合题意，故选C。

【3】考查对上下文的理解及推理判断能力。根据Have a look下面一段最后一句“we call the smaller particles PM 2.5（称较小的颗粒为pm2.5）”，结合空格前的“The small particles are smaller than 2.5 micrometers” 这些小颗粒小于2.5微米。可知这些小于2.5微米的叫做PM2.5。可推断出A项These particles are called PM 2.5.（这些粒子叫做PM 2.5）是 符合题意的，故选A。

【4】考查对上下文的理解及推理判断能力。空格前提到And travel? 空格后面PM 2.5 particles go even farther; many hundreds of miles（PM 2.5粒子甚至走得更远；数百英里），even farther含比较的意思，综合看可知，空格处应该是提到PM 10可以漂浮到多远。分析选项可知D. PM 10 particles can travel as much as 30 miles（ PM 10粒子的行程可达30英里）符合题意，故选D。

【5】考查对上下文的理解及推理判断能力。前文提到“The smaller particles are lighter and they stay in the air longer and travel farther”更小的颗粒更轻，它们在空气中停留的时间更长，移动的距离更远。而本段小标题为Particulate Matter and Your Health可知本段谈颗粒对人类健康造成影响，以及空格后“Exposure to particulate matter leads to increased use of medication and more visits to the doctor or emergency room.”暴露在颗粒物中会导致用药增加，去看医生或急诊室的次数增加。既然小颗粒在空中呆的时间更长，飘的更远，自然危害更大。分析选项可知，F选项PM 2.5 can have worse health effects than the bigger PM 10. （PM 2.5对健康的影响比较大的PM 10）更严重，符合题意，故选F。