Part I: Finish each of the following sentences in such a way that it means the same as the sentence printed before it

-Susan: "_______.”

C. I feel very bored

D. I don't agree, I'm afraid

C. Because of she quarreled

D. Had quarreled

C. phoned/ was writing

D. was phoning/ wrote

A B C D

A B C D

A B C

D

A B C

D

In the past, traffic lights were special. In New York, some lights had a statue on top. In Los Angeles the lights did not just (43) ______ silently, but would ring bells to (44) ______the sleeping motorists of the 1930s. These are gone and have been replaced by standard models which are universally adopted.

Large animals that inhabit the desert have evolved a number of adaptations for reducing the effects of extreme heat. One adaptation is to be light in color, and to reflect rather than absorb the Sun’s rays. Desert mammals also depart from the normal mammalian practice of maintaining a constant body temperature. Instead of trying to keep down the body temperature deep inside the body, which would involve the expenditure of water and energy, desert mammals allow their temperatures to rise to what would normally be fever height, and temperatures as high as 46 degrees Celsius have been measured in Grant’s gazelles. The overheated body then cools down during the cold desert night, and indeed the temperature may fall unusually low by dawn, as   low as 34 degrees Celsius in the camel. This is an advantage since the heat of the first few hours of daylight is absorbed in warming up the body, and an excessive buildup of heat does not begin until well into the day.

Another strategy of large desert animals is to tolerate the loss of body water to a point that would be fatal for non-adapted animals. The camel can lose up to 30 percent of its body weight as water without harm to itself, whereas human beings die after losing only 12 to 13 percent of their body weight. An equally important adaptation is the ability to replenish this water loss at one drink. Desert animals can drink prodigious volumes in a short time, and camels have been known to imbibe over 100 liters in a few minutes. A very dehydrated person, on the other hand, cannot drink enough water to rehydrate at one session, because the human stomach is not sufficiently big and because a too rapid dilution of the body fluids causes death from water intoxication. The tolerance of water loss is of obvious advantage in the desert, as animals do not have to remain near a water hole but can obtain food from grazing sparse and far-flung pastures. Desert-adapted mammals have the further ability to feed normally when extremely dehydrated, it is a common experience in people that appetite is lost even under conditions of moderate thirst.

B. Adaptations of desert animals.

D. Human use of desert animals.

B. It does not absorb sunlight as much as dark colors

D. It keeps them cool at night.

B. In the middle of the day                 

D. Just after drinking                        

B. Drinking polluted water.

D. Lack of water.

B. To contrast them to desert mammals

D. To show how they have adapted to desert life.

An air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely. Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled - a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of the health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions.

Many of the more important air pollutants, such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentration of these pollutants was altered by various chemical reactions; they became components in biogeochemical cycles. These serve as an air purification scheme by allowing the compounds to move from the air to the water or soil. On a global basis, nature's output of these compounds dwarfs that resulting from human activities.

However, human production usually occurs in a localized area, such as a city. In such a region, human output may be dominant and may temporarily overload the natural purification scheme of the cycles. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact, the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, has a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.

B. What constitutes an air pollutant

D.The effects of compounds added to the atmosphere

B. most air pollutants today can be seen or smelled

C. the definition of air pollution will continue to change

D. a substance becomes an air pollutant only in cities

B. the pollutants from the developing Earth

D. the components in biogeochemical cycles

B. They occur in greater quantities than other pollutants.

C. They are less harmful to living beings than other pollutants.

D. They have existed since the Earth developed

B. can overwhelm the natural system that removes pollutants

C. will damage areas outside of the localized regions

D. will react harmfully with natural pollutants

D. it can be calculated quickly

B. One of the most important steps in preserving natural lands is to better enforce air pollution laws.

C. Scientists should be consulted in order to establish uniform limits for all air pollutants.

D. Human activities have been effective in reducing air pollution.