Question

    As the COVID-19 pandemic （新冠肺炎）rages, with ongoing lockdown （封城）measures affecting millions of people around the globe, levels of air pollution are falling dramatically in many parts of the world. This trend has been highlighted by a new report published by Swiss company IQAir looking at ten key global cities that normally suffer from high levels of pollution.

The report compared measurements from ground-based monitoring stations regarding a type of pollutant known as PM2.5— tiny inhalable particles measuring 2.5 micrometers or smaller that are emitted （排放）by various sources such as vehicles and power plants. It found significant falls in nearly all the locations listed.

This is, perhaps, not surprising considering the large decreases in vehicle traffic and industrial activity that have occurred with lockdown measures imposed （实施）on these cities.

The report examined data collected over a three-week period for each city while they were under lockdown conditions. IQAir then compared these measurements to the same time period for the years between 2016 and 2019.

IQAir found that nine out of the ten cities in the report experienced significant reductions in PM2.5 compared to the same period for 2019. Those with historically higher levels of PM2.5 pollution saw the greatest drops including New Delhi （-60 percent） Seoul （-54 percent） and Wuhan （-44 percent）. Besides, seven of the cities saw reductions in PM2.5 of 25 to 60 percent compared to the same period last year.

Wuhan—where the COVID-19 pandemic was first identified—experienced the cleanest air on record for February and March. The city was placed under one of the strictest lockdowns in the world on January 24, which was only lifted after 10 weeks.

Unfortunately, these sharp improvements in air quality have coincided （同时发生）with significant economic disruption, suffering and loss of life across the globe. Furthermore, experts warn that without sustained action to control pollution once the crisis ends, levels will likely rebound, as has been witnessed following previous economic downturns.

1.The levels of air pollution in the nine cities drop dramatically probably because                 .

A.the global economy suffers downturns

B.vehicle traffic and industrial activity decrease sharply during the pandemic

C.the governments of these cities take effective measures to reduce air pollution

D.people around the world have raised their awareness of environmental protection

2.Why does the author list the numbers in paragraph 5?

A.To show the data from IQAir are true.

B.To make a comparison between the cities.

C.To show the significant reductions in levels of air pollution.

D.To prove the measures carried out in these cities are effective.

3.What does the underlined word "disruption” in the last paragraph mean?

A.destruction B.eruption

C.break D.construction

4.What is the main idea of the passage?

A.The introduction of PM2.5.

B.The COVID-19 pandemic has caused great loss across the globe.

C.IQAir measured the air pollution levels in major global cities during the pandemic.

D.Air pollution has fallen significantly in nine major global cities during the pandemic.

Answer

1.B

2.C

3.A

4.D

【解析】

本文一篇说明文。介绍在疫情期间，IQAir监测到全球9个大城市的空气污染水平急剧下降，但文章也同时指出这是以全球经济遭受重大破坏和许多生命逝去为代价的。

1.

细节理解题。根据第二段及第三段“This is, perhaps, not surprising considering the large decreases in vehicle traffic and industrial activity that have occurred with lockdown measures imposed on these cities. ”可知，考虑到这些城市实施的封锁措施，导致机动车交通和工业活动大幅减少，这也许并不令人惊讶。所以这九大城市空气污染水平急剧下降是因为封城而导致交通以及工业活动的减少造成的。故选B。

2.

推理判断题。根据第五段“IQAir found that nine out of the ten cities in the report experienced significant reductions in PM2.5 compared to the same period for 2019. Those with historically higher levels of PM2.5 pollution saw the greatest drops including New Delhi （-60 percent） Seoul （-54 percent） and Wuhan （-44 percent）. Besides, seven of the cities saw reductions in PM2.5 of 25 to 60 percent compared to the same period last year.”IQAir发现，报告中10个城市中有9个城市的PM2.5浓度与2019年同期相比大幅下降。历史上PM2.5污染水平较高的城市降幅最大，包括新德里(下降60%)、首尔(下降54%)和武汉(下降44%)。此外，其中7个城市的PM2.5同比下降了25%到60%。由此判断出五段列举这些数字的目的是为了表明这些城市空气污染水平下降的程度非常大。故选C。

3.

词义猜测题。根据划线处后面“suffering and loss of life across the globe”可知，全世界都在遭受痛苦和丧失生命。所以不幸的是，这些空气质量的急剧改善与全球经济的严重破坏、苦难和生命的丧失同时发生。由此判断出划线词的意思是“破坏”。故选A。

4.

主旨大意题。通读全文尤其是第一段“As the COVID-19 pandemic （新冠肺炎）rages, with ongoing lockdown （封城）measures affecting millions of people around the globe, levels of air pollution are falling dramatically in many parts of the worl”第五段“IQAir found that nine out of the ten cities in the report experienced significant reductions in PM2.5 compared to the same period for 2019. ”可知，随着COVID-19大流行的肆虐，持续的封锁措施影响着全球数百万人，世界许多地区的空气污染水平正在急剧下降。IQAir发现，报告中10个城市中有9个城市的PM2.5浓度与2019年同期相比大幅下降。所以本文主要介绍了在疫情期间，全球9个大城市的空气污染水平急剧下降的情况。故D正确。