A recent report has suggested that air pollution in our big cities could be damaging to our health. The report put forward practical tips that city people can take to reduce their exposure （暴露） to city air pollution. Quite a lot, it turns out.

◙ Watch where you walk

       Avoid walking along busy streets, instead choosing side streets and parks because pollution levels can fall by a factor of 10 just by moving a few metres away from the main source of the pollution - exhaust fumes （难闻的气味）.

       Don't walk behind smokers, and walk on the windward（迎风）, side of the street where exposure to pollutants （污染源） can be 50% less than on the leeward （背风） side.

◙ Pavement （人行道） sense 

       When you're crossing a road, stand well back from the kerb （路边石） while you wait for the lights to change. Every meter really does count when you are close to traffic. As the traffic moves, the gases can disappear in just a few seconds, particularly if the wind is up, which means holding your breath during this period can make a difference, silly as that might sound. Besides, cross the road as quickly as possible. And once you're over, continue along the pavement as far away from the kern as possible.

◙ Where to sit on the bus

       Sitting on the driver's side of a bus can increase your exposure by 10% compared with sitting on the side nearest to the pavement. And sitting upstairs on a double-decker can reduce your exposure too. It's difficult to say whether traveling on an underground train is better or worse than taking the bus, but the air pollution on underground trains tends to be less toxic （有毒的） by weight than that found at street level.

◙ Wear a mask （口罩）

1．The best title for the passage probably would be________.

       A．How to make our life easy

       B．How to reduce the exposure to city air pollution

       C．The ways to deal with city pollution

       D．We should draw a lesson from city air pollution

2．Which of the following is the author’s opinion according to the passage?

    A．There is no way to escape from air pollution.

    B．We shouldn’t travel on an underground or a bus.

    C．We must reduce air pollution to live in the city.

    D．We must try to protect ourselves from city air pollution.

3．Which of the following is TRUE according to the passage?

    A．When you are close to traffic, it is not advisable to hold your breath a while.

    B．Cross the street as quickly as possible when waiting for the light to change

    C．Traveling on an underground train is better than taking the bus.

    D．Don’t get close to traffic whenever it is possible.

4．The word “neutralize” underlined in the last paragraph probably means _______.

       A．cut down        B．add to        C．lead to       D．get into

A recent report has suggested that air pollution in our big cities could be as damaging to our health. The report put forward practical tips that city people can take to reduce their exposure (暴露) to city air pollution. Quite a lot, it turns out.

◙ Watch where you walk

Avoid walking along busy streets and thoroughfares (大街), instead choosing side streets and parks. because pollution levels can fall by a factor of 10 just by moving a few metres away from the main source of the pollution - exhaust fumes. "

Don't walk behind smokers, and walk on the windward迎风, side of the street where exposure to pollutants污染源 can be 50% less than on the leeward背风side. 

◙ Pavement(人行道) sense 

When you're crossing a road, stand well back from the kerb(路边石)while you wait for the lights to change. Every metre really does count when you are close to traffic. As the traffic moves, the gases can disappear in just a few seconds, particularly if the wind is up, which means holding your breath during this period can make a difference, silly as that might sound. Besides, cross the road as quickly as possible. And once you're over, continue along the pavement as far away from the kerb as possible.

◙ Where to sit on the bus

Sitting on the driver's side of a bus can increase your exposure by 10% compared with sitting on the side nearest to the pavement. And sitting upstairs on a double-decker can reduce your exposure too. It's difficult to say whether travelling on an underground train is better or worse than taking the bus, but the air pollution on underground trains tends to be less toxic(有毒的)by weight than that found at street level.

◙ Wear a mask(口罩)

Masks can be a good thing, but they only make a difference if they fit tightly and are cleaned regularly. Even the slightest gap to allow you to breathe more easily will neutralize any advantages. Worse, if you fail to clean or change the mask regularly, something dangerous can form on the mask. So the air you breathe is dirtier rather than cleaner.

68. The best title for the passage probably would be________.

    A. How to make our life easy and at ease

    B. How to reduce the exposure to city air pollution.

    C. The ways to deal with city pollution

    D. We should draw a lesson from city air pollution

69. Which of the following is the author’s opinion according to the passage?

    A. there is no way to escape from air pollution

    B. we shouldn’t travel on an underground or a bus.

    C. we must reduce air pollution to live in the city

    D. we must try to protect ourselves from city air pollution.

70. Which of the following is NOT TRUE according to the passage?

    A. when you are close to traffic, it is not advisable to hold your breath a while

    B. Cross the street as quickly as possible when waiting for the light to change

    C. Travelling on an underground train is better than taking the bus.

    D. Don’t get close to traffic whenever it is possible.

71. The word “neutralize” underlined in the last paragraph probably means_________.

    A. cut down    B. add to    C. lead to   D. get into