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

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

阅读理解

　　Light travels at a speed which is about a million times faster than that of sound. In one second, light travels about 300,000 kilometers, but sound travels only 344 metros. You can get some idea of this difference by watching the start of a running match. If you stand quite away from the starter（发令员）, you can see smoke come from his gun before the sound reaches your ears.

　　The fast speed of light produces some strange facts. Sunlight takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light rays（射线）left the moon 1.3 seconds before they reached you. The nearest star is so far away that the light which you can see from it tonight to travel to you 4 years ago at a speed of nearly 2 million kilometers every minute. The light from some of tonight’s stars started on its journey towards you even before you were born.

　　Thus, if we want to be honest, we cannot say, “The stars are shining brightly tonight.” We have to say, “The stars look pretty. They were shining four years ago but their light has just reached out earth.”

1. The best title（题目）of this passage is ________.

[　　]

A. Light Travels Faster than Sound

B. Stars Are Very Far Away from us

C. The Speed of Light

D. It’s Not Correct to Say “The Stars Are Shining Brightly Tonight”

2. If you stand 200 metros away from a man who is firing a gun to start a running match, you will find out that ________.

[　　]

A. light travels a million times faster than sound

B. the smoke of the gun gets into your sight after the sound of the gun-shot

C. sound travels less fast than light

D. the sound of the gun will reach you at the same time with the light of the smoke

3. Sunlight obviously ________ than the light of the moon.

[　　]

A. has to travel a greater distance

B. moves less quickly

C. travels much more quickly

D. is less powerful

4. The scientific way of saying “The stars are shining brightly tonight” should be ________.

[　　]

A. the stars have been shining all the time

B. the stars seen tonight will be shining four years later

C. the stars were shining long ago but are seen tonight

D. the star light seen tonight could be seen four years ago

5. The light of the nearest star you see tonight has been ________ for years.

[　　]

A. on the earth　　　　    B. on the moon

C. away from the sun　　   D. away from itself

Light travels at a speed which is about a million times faster than the speed of  sound. You can get some idea of this difference by watching the start of a race. If    you stand some distance away from the starter, you can see smoke from his gun      before the sound reaches your ears.

This great speed of light produces some strange facts. Sunlight takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light   rays left the moon 1.3 seconds before they reached you. The nearest star is so far  away that the light that you can see from it tonight started to travel towards you    four years ago at a speed of nearly 2 million km. per minute. In some cases, the    light from one of tonight’s stars had started on its journey to you before you were born.

Thus, if we want to be honest, we can’t say, “The stars are shining tonight.” We   have to say instead, “The stars look pretty. They were shining four years ago, but    their light has only just reached the earth.”

1. Light speed is ______ sound speed

2.If you stand 200 meters away from a man who is firing a gun to start a race, you will find out that ______.

3.Sunlight obviously (明显地) ______ than the light of the moon

4.The scientific way of saying "The stars are shining tonight" should be ______.