1 . Natural selection is the process by which one type of animal within a species thrives (兴旺) because of certain characteristics that make it more likely to live than others in its group. The history of the peppered moth (灰蛾) is an example of the natural selection process.

In nineteenth-century England, certain types of peppered moths were able to better blend (融合) into their surroundings. During that time period, great changes were happening in Great Britain. The Industrial Revolution was part of this change, and with it came air pollution. Natural selection often takes hundreds or even thousands of years to occur. For the peppered moth, this process occurred comparatively quickly.

At the beginning of the Industrial Age, most peppered moths in England were light-colored and covered with black markings, although a few moths had dark-colored wings. Because the light-colored moths blended into the light-colored bark on the trees, they could not be easily seen by birds that would eat them. As the air grew more polluted, however, tree trunks became covered with soot (煤烟) and became darker. The light-colored moths became easy for birds to see against the dark tree trunks. Since the dark-colored moths now had the advantage, their numbers grew. Within 50 years, the peppered moth went from being mostly light-colored to being mostly dark-colored.

In the twentieth century, the air cleared up, and the peppered moth population changed again. As tree trunks lightened due to less soot in the air, light-colored moths once again had an advantage. Their numbers increased as soot levels declined. Depending on their environment, the coloration of the moths helped them to be “naturally selected” to survive.

1. What do we know about the peppered moth’s natural selection process?

A．It was a good example of environmental protection.

B．The soot levels in England did not affect it.

C．This type of color change was typical for moths.

D．The length of time was unusual.

2. What can we learn from the third paragraph?

A．Both kinds of moths preferred the dark-colored trees.

B．Birds failed to see light-colored moths.

C．There were more light-colored moths than dark-colored moths originally.

D．The color of moths was unimportant.

3. Which would most likely happen if soot darkened England’s trees again?

A．Birds would eat fewer moths.

B．The population of dark-colored moths would increase.

C．Moths would not be able to stay alive.

D．Light-colored moths would disturb people’s life.

4. We can infer from the text that in England ________     .

A．there were always many peppered moths

B．birds preferred to eat dark-colored moths

C．trees changed colors to adapt to the environment

D．birds were dangerously affected by the soot levels

2 . One of the problems damaging our planet is the number of things we throw away. A more recent addition to the list of things we throw away is e-waste —   electronic items that are broken and not recycled.     1    , but also because we lack the skills to repair them even if we know their value. Many millions of tons of televisions, phones, and other electronic equipment are abandoned each year. A UN report claims the 50 million tons of e-waste generated every year will more than double to 110 million tons by 2050, making it the fastest growing waste stream in the world.     2    .

Recently, there’s a growing trend for repair events and clubs which could be part of a solution to the growing amount of electrical and electronic junk. The BBC visited a Restart Project in London, which is one of many found around the world. One of its operators, Francesco Calo, said that “This project makes total sense.     3    . Besides, it helps people who cannot afford to get rid of items that have developed a fault.”

    4    . An experiment at the University of New South Wales involves extracting (提取) these materials from electronic gadgets (小工具). Apart from just being recycled, the European Union, for example, is trying to encourage manufacturers to reuse some extracted electronic components.     5    . With phones typically containing as many as 60 elements, this could be part of the solution to our appetite for new technology.

A．First of all, this project prolongs the life of electric objects

B．It is partly because it’s cheaper to replace them than fix them

C．It is reported that many people have made a big fortune from it

D．Now solutions have been put forward to give this e-waste a new life

E．So it’s thought that doing this could be more profitable than traditional recycling

F．As many electrical items contain valuable metals, another solution is e-waste mining

G．One of the reasons is that people don’t think their electronic items are fashionable enough

3 . Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. But there is another factor that can cause your heart problems more immediately：the air you breathe.

Previous studies have linked high exposure (暴露) to environmental pollution to an increased risk of heart problems，but two analyses now show that poor air quality can lead to heart attack or stroke (中风) within as little as a few hours after exposure. In one review of the research, scientists found that people exposed to high levels of pollutants (污染物) were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure. A separate study of stroke patients showed that even air that the U. S. Environmental Protection Agency (EPA)considers to be of “moderate” (良好) quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure.

The authors of both studies stress that these risks are relatively small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure. However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices. So stricter regulation by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.

1. The text mainly discusses the relationship between ________.

A．heart problems and air quality

B．heart problems and exercising

C．heart problems and smoking

D．heart problems and fatty food

2. The underlined word “modest” in Paragraph 3 most probably means ________.

A．relatively high	B．extremely low
C．relatively low	D．extremely high

3. What can we learn from the text?

A．Eating fatty food has immediate effects on your heart.

B．The EPA conducted many studies on air quality.

C．Moderate air quality is more harmful than smoking.

D．Stricter regulations on pollutants should be made.

4. The author's purpose of writing the text is most likely to ________.

A．inform	B．persuade
C．describe	D．entertain