It doesn't take a rocket scientist long time to figure out that there are better things you could do for your health than take deep breaths on a smoggy（烟雾的）day. A growing pile of research suggests that even relatively low levels of air pollution may be more harmful than previously realized, to both heart and lungs(肺). The latest articles from researchers, published this week in the New England Journal of Medicine, focuses on how particulate (微粒) matter from air pollution affects lung function.
“The effect of low levels of particulate pollution found in many urban areas is not unlike secondhand smoke,” experts say. Studies show that short-term effects from particulates include diminished（减少） lung function, coughing, wheezing, and heart attacks. Long-term exposure can also slow normal lung growth, damage lung airways, and increase the risk of dying from lung cancer.
Certain populations, such as the very old and the very young, are the most vulnerable to air pollution. However, even the most alarming studies conducted in the most polluted areas suggest that the average person's individual risk from exposure (暴露) is very slight. Relative risk numbers often seem more frightening than they actually are. For example, an earlier study published in the New England Journal of Medicine found that short-term exposure to traffic fumes tripled ( 成为3倍) the risk of heart attacks in heart-attack survivors.
Short of moving to the countryside or at least away from busy roads, shielding yourself from the effects of air pollution is not easy. Masks won't work. “At the very least,” suggests Murray Mittleman, a cardiologist at Harvard University, “people who regularly exercise outdoors near highways may want to consider remapping their route.”
66. What does the underlined sentence in the first paragraph mean?
A. Rocket scientists are making researches on people’s health.
B. It's obvious that air pollution has a bad effect on people’s health.
C. People aren't sure whether taking deep breaths on a smoggy day is bad.
D. People often have a hard time when taking deep breaths on a smoggy day.
67. The word "vulnerable" in Paragraph 3 probably means _________.
A. easy to be hurt            B. easy to be protected
C. easy to be used            D. easy to be saved
68. The main idea of Paragraph 3  is _________.
A. that even small risk from particulate causes big problems
B. that air pollution often leads to heart attack
C. who are most likely to get affected
D. that we shouldn't worry about the average low risk
69. In order to be healthier, you'd better _________.
A. take deep breaths         B. wear a mask   
C. live in a countryside       D. clean the busy road
70. The passage is written in a(n) _________ tone.
A. subjective         B. humorous     C. doubtful      D. objective

It doesn't take a rocket scientist long time to figure out that there are better things you could do for your health than take deep breaths on a smoggy（烟雾的）day. A growing pile of research suggests that even relatively low levels of air pollution may be more harmful than previously realized, to both heart and lungs(肺). The latest articles from researchers, published this week in the New England Journal of Medicine, focuses on how particulate (微粒) matter from air pollution affects lung function.

“The effect of low levels of particulate pollution found in many urban areas is not unlike secondhand smoke,” experts say. Studies show that short-term effects from particulates include diminished（减少） lung function, coughing, wheezing, and heart attacks. Long-term exposure can also slow normal lung growth, damage lung airways, and increase the risk of dying from lung cancer.

Certain populations, such as the very old and the very young, are the most vulnerable to air pollution. However, even the most alarming studies conducted in the most polluted areas suggest that the average person's individual risk from exposure (暴露) is very slight. Relative risk numbers often seem more frightening than they actually are. For example, an earlier study published in the New England Journal of Medicine found that short-term exposure to traffic fumes tripled ( 成为3倍) the risk of heart attacks in heart-attack survivors.

Short of moving to the countryside or at least away from busy roads, shielding yourself from the effects of air pollution is not easy. Masks won't work. “At the very least,” suggests Murray Mittleman, a cardiologist at Harvard University, “people who regularly exercise outdoors near highways may want to consider remapping their route.”

66. What does the underlined sentence in the first paragraph mean?

A. Rocket scientists are making researches on people’s health.

B. It's obvious that air pollution has a bad effect on people’s health.

C. People aren't sure whether taking deep breaths on a smoggy day is bad.

D. People often have a hard time when taking deep breaths on a smoggy day.

67. The word "vulnerable" in Paragraph 3 probably means _________.

A. easy to be hurt            B. easy to be protected

C. easy to be used            D. easy to be saved

68. The main idea of Paragraph 3  is _________.

A. that even small risk from particulate causes big problems

B. that air pollution often leads to heart attack

C. who are most likely to get affected

D. that we shouldn't worry about the average low risk

69. In order to be healthier, you'd better _________.

A. take deep breaths         B. wear a mask   

C. live in a countryside       D. clean the busy road

70. The passage is written in a(n) _________ tone.

A. subjective         B. humorous     C. doubtful      D. objective

It doesn't take a rocket scientist long time to figure out that there are better things you could do for your health than take deep breaths on a smoggy（烟雾的）day. A growing pile of research suggests that even relatively low levels of air pollution may be more harmful than previously realized, to both heart and lungs(肺). The latest articles from researchers, published this week in the New England Journal of Medicine, focuses on how particulate (微粒) matter from air pollution affects lung function.

“The effect of low levels of particulate pollution found in many urban areas is not unlike secondhand smoke,” experts say. Studies show that short-term effects from particulates include diminished（减少） lung function, coughing, wheezing, and heart attacks. Long-term exposure can also slow normal lung growth, damage lung airways, and increase the risk of dying from lung cancer.

Certain populations, such as the very old and the very young, are the most vulnerable to air pollution. However, even the most alarming studies conducted in the most polluted areas suggest that the average person's individual risk from exposure (暴露) is very slight. Relative risk numbers often seem more frightening than they actually are. For example, an earlier study published in the New England Journal of Medicine found that short-term exposure to traffic fumes tripled ( 成为3倍) the risk of heart attacks in heart-attack survivors.

   Short of moving to the countryside or at least away from busy roads, shielding yourself from the effects of air pollution is not easy. Masks won't work. “At the very least,” suggests Murray Mittleman, a cardiologist at Harvard University, “people who regularly exercise outdoors near highways may want to consider remapping their route.”

66. What does the underlined sentence in the first paragraph mean?

    A. Rocket scientists are making researches on people’s health.

    B. It's obvious that air pollution has a bad effect on people’s health.

    C. People aren't sure whether taking deep breaths on a smoggy day is bad.

    D. People often have a hard time when taking deep breaths on a smoggy day.

67. The word "vulnerable" in Paragraph 3 probably means _________.

     A. easy to be hurt             B. easy to be protected

     C. easy to be used             D. easy to be saved

 68. The main idea of Paragraph 3  is _________.

      A. that even small risk from particulate causes big problems

      B. that air pollution often leads to heart attack

      C. who are most likely to get affected

      D. that we shouldn't worry about the average low risk

 69. In order to be healthier, you'd better _________.

A. take deep breaths         B. wear a mask   

C. live in a countryside       D. clean the busy road

70. The passage is written in a(n) _________ tone.

A. subjective         B. humorous      C. doubtful      D. objective

During the 19th century, scientists found that when certain parts of the brain of a person were hurt, he would lose the power of doing certain things. And so people thought that each part of the brain does a different job. But modern research has discovered that this is not so, for it is not easy to show exactly what each part of the brain does.

In the past fifty years there has been a great increase in the amount or research done on the brain. Scientists have found out that the way the brain works is not so simple as people in general may think. Chemists tell us that about 100,000 chemical changes take place in the brain every second. Some recent researches also suggest that we can remember everything that happened to us. We may not be able to think of the things we have heard and seen but it is kept there in the store-house of the human mind. Earlier scientists thought that the power of one’s brain got weaker and weaker as one grows older. But it is plenty of exercise, it keeps its power. It is now thought that is not true. As long as the brain is given plenty of exercise, it keeps its power. It has proved that an old person who has always been active in the mind has a quicker mind than a young person who has done physical work without using much of his brain.

1.In the last century, scientists found that a person would lose the power to do certain things _____.

A．when he got weaker in health

B．if certain parts of his brain were hurt

C．after he did a quite different job

D．when he grew older

2.Scientists today are still unable to show exactly ______.

A．what each part of the brain is doing

B．how many chemical changes take place in the brain each second

C．whether each part of the brain does the same job

D．which part of the brain is the most important

3.It has been found that one’s brain usually works ______.

A．faster when he is old

B．a little now and a little then

C．in a very simple way

D．without any rest all day long

4.Which of the following is NOT true according to the text?

A．Scientists are working hard at the researches on the brain.

B．As many as six million chemical changes take place in the brain every minute.

C．A young man doing physical labor is sure to have a much slower mind.

D．Even an old man has a quick mind only if his brain is given much exercise.

5.The more work we give our brains,___________.

A．the less result we will gain

B．the more work they are able to do

C．the weaker their power will get

D．the more tired they will feel

During the 19th century, scientists found that when certain parts of the brain of a person were hurt, he would lose the power of doing certain things. And so people thought that each part of the brain does a different job. But modern research has discovered that this is not so, for it is not easy to show exactly what each part of the brain does.

In the past fifty years there has been a great increase in the amount or research done on the brain. Scientists have found out that the way the brain works is not so simple as people in general may think. Chemists tell us that about 100,000 chemical changes take place in the brain every second. Some recent researches also suggest that we can remember everything that happened to us. We may not be able to think of the things we have heard and seen but it is kept there in the store-house of the human mind. Earlier scientists thought that the power of one’s brain got weaker and weaker as one grows older. But it is plenty of exercise, it keeps its power. It is now thought that is not true. As long as the brain is given plenty of exercise, it keeps its power. It has proved that an old person who has always been active in the mind has a quicker mind than a young person who has done physical work without using much of his brain.

51.In the last century, scientists found that a person would lose the power to do certain things _____.

A. when he got weaker in health

B. if certain parts of his brain were hurt

C. after he did a quite different job

D. when he grew older

52. Scientists today are still unable to show exactly ______.

A. what each part of the brain is doing

B. how many chemical changes take place in the brain each second

C. whether each part of the brain does the same job

D. which part of the brain is the most important

53. It has been found that one’s brain usually works ______.

A. faster when he is old            B. a little now and a little then

C. in a very simple way             D. without any rest all day long

54. Which of the following is NOT true according to the text?

A. Scientists are working hard at the researches on the brain.

B. As many as six million chemical changes take place in the brain every minute.

C. A young man doing physical labor is sure to have a much slower mind.

D. Even an old man has a quick mind only if his brain is given much exercise.

55. The more work we give our brains,___________.

A. the less result we will gain        B. the more work they are able to do

C. the weaker their power will get     D. the more tired they will feel