(Q).
Read the following article and select the best answer. Article: Scientists are closely concerned with the structure of buildings and with the quality of building materials. The World health Organization (WHO) observes that the introduction of air conditioning and energy conservation measures have been accompanied by growing problems of indoor air quality. Some pollutants arise from insulation products, some from moving cars, and others from modern housing materials. As many Europeans spend up to 90% of their lives in buildings, the health effects of the indoor climate are very important. Some construction materials, including fiberboard, insulation foams and certain glues for man-made wood floor boards, for example, give out organic products such as formaldehyde . Heat and humidity increase the release of formaldehyde and the gas seriously harms the eyes. Paint, lacquer, etc. can also release dangerous gas into indoor air. Construction materials can cause serious damage, especially when they contain asbestos . Asbestos is naturally present in rock formations worldwide. It belongs to a family of mineral substances made up of solid, non-combustible fiber. These properties make asbestos a highly sought-after construction material. As early as 1931, however, public health officers in the prefix = st1 /United Kingdomrevealed the connection between breathing in asbestos dust and such diseases as lung cancer. The land on which a building is sited may also contribute to pollution. Some kinds of granite or similar rocks contain traces of radium. As it breaks down, this naturally radioactive element produces some kind of radioactive gas that goes through tiny cracks in walls, floors and building materials, and makes its way into the building and the rooms. The better the homes are insulated, the more is the dangerous gas in indoor air. The main effect of this dangerous gas on health is to increase the risk of lung cancer. Question: Why are Europeans particularly concerned with building materials? - Lots of building materials there are radioactive. - They stay home up to 90% of their lives. - They have a high rate of lung cancer. - They spend most of their time indoors.
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They spend most of their time indoors.

(Q).
Read the following article and select the best answer. Article: Before the mid 1860's, the impact of the railroads in the United States was limited, in the sense that the tracks ended at this Missouri River, approximately the center of the country. At the point thetrains turned their freight, mail, and passengers over to steamboats, wagons, and stagecoaches. This meant that wagon freighting, stage coaching, and steam boating did not come to an end when the first train appeared; rather they became supplements or feeders. Each new "end of track" became a center for animal drawn or waterborne transportation. The major effect of the railroad was to shorten the distance that had to be covered by the older, slower, and more costly means. Wagon freighters continued operating throughout the 1870's and 1880's and into the 1890's. Although over constantly shrinking routes, and coaches and wagons continued to crisscross the West wherever the rails had not yet been laid. The beginning of a major change was foreshadowed in the later 1860's, when the Union Pacific Railroad at last began to build westward from the Central Plains city of Omaha to meet the Central Pacific Railroad advancing eastward from California through the formidable barrier of the Sierra Nevada. Although President Abraham Lincoln signed the original Pacific Railroad bill in 1862 and a revised, financially much more generous version in 1864, little construction was completed until 1865 on the Central Pacific and 1866 on the Union Pacific. The primary reason was skepticism that a Railroad built through so challenging and thinly settled a stretch of desert, mountain, and semiarid plain could pay a profit. In the words of an economist, this was a case of "premature enterprise", where not only the cost of construction but also the very high risk deterred private investment. In discussing the Pacific Railroad bill, the chair of the congressional committee bluntly stated that without government subsidy no one would undertake so unpromising a venture; yet it was a national necessity to link East and West together. Question: What can be inferred about coaches and wagon freighters as the railroad expanded? - They developed competing routes. - Their drivers refused to work for the railroads. - They began to specialize in private investment. - There were insufficient numbers of trained people to operate them.
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There were insufficient numbers of trained people to operate them.

(Q).
Read the following article and select the best answer. Article: Normally, about 10 percent of the hair on your head is resting (not growing). After a few months, the resting hair falls out and new hair begins to grow in its place. The growing time can last from 2 to 6 years. During the growing period, hair will gain about 1 centimeter a month. It is normal to experience hair loss every day. Some people experience too much hair loss from a variety of causes. Most people _ believe that hair loss is caused by things like stress, scalp ,or wearing hats. With the exception of stress, none of these factors has been proven to be a cause of hair loss. Stress is also not very likely unless you have experienced extreme physical or psychological suffering. This hair loss also doesn't last long. The real cause of hair loss lies with hormonal problems. Hair loss occurs when male or female hormones are out of balance. An imbalance of hormones is usually genetic and cannot be cured. Male and female-pattern baldness is the most common form of hair loss. This is caused by a hormone called DHT, which helps in sexual development. An increase in DHT in a grown-up can lead to hair loss. There are also other causes of hair loss. Blood-thinners, some kind of medicines, and an excess of vitamin A, have all been shown to increase hair loss in certain people. Infections of the scalp can cause hair loss as well as certain diseases like diabetes. Question: What is this passage mainly about? - The side effects of medicines. - The effects of hormones. - The causes of hair loss. - Some ways to protect your hair.
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The causes of hair loss.