TASK DEFINITION: In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". Do not generate anything else apart from one of the following characters: "A", "B", "C", "D". There is only one correct answer for each question.
PROBLEM: Article: Different kinds of soil conservation methods are used by farmers to protect their land from damage by farming and the forces of nature. One important form of soil conservation is the use of windbreaks. Windbreaks are barriers formed by trees and other plants with many leaves. Farmers plant them in lines around their fields. Windbreaks stop the wind from blowing soil away. They also keep the wind from destroying or damaging crops. They are very important for growing grains, such as wheat. There have been studies done on windbreaks in parts of West Africa, for example. They found that grain harvests can be twenty percent higher in fields protected by windbreaks compared to fields without such protection. However, windbreaks seem to work best when they allow a little wind to pass through. If the wall of trees and plants stops wind completely, then violent air motions will take place close to the ground. These motions will lift soil into the air where it will be blown away. For this reason, a windbreak is best if it has only sixty to eighty percent of the trees and plants needed to make a solid line. There should be at least two lines in each windbreak. One line should be large trees. The second line, right next to it, can be shorter trees and other plants with leaves. Locally grown trees and plants are best for windbreaks.
Question: What is a windbreak according to the passage?
Options: (A) A windbreak is a concrete wall to prevent the strong winds. (B) A windbreak is a wood with different kinds of trees. (C) A windbreak is a wall of trees to hold soil in place. (D) A windbreak is a wall of wind to fight wind from the opposite way.

SOLUTION: C

PROBLEM: Article: In the atmosphere, carbon dioxide acts rather like a one-way mirror or the glass in the roof of a greenhouse which allows the sun's rays to enter but prevents the heat from escaping According to a weather expert's prediction , the atmosphere will be 3degC warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate.If this warming up took place.the ice caps in the poles would begin to inch,thus raising sea level several meters and severely flooding coastal cities.Also.the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere ,possibly resulting in an alteration of the earth's chief food growing zones. In the past,concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet.But the weather experts are now paying more attention to West Antarctic.which may be affected by only a few degrees of warming,in other words,by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels. Satellite pictures show that large areas of Antarctic ice are already disappearing.The evidence available suggests that a warming has taken place.This fits the theory that carbon dioxide warms the earth. However, most of the fuel is burnt in the northern hemisphere,where temperatures seem to be falling.Scientists conclude,therefore ,that up to now natural influences on the weather have gone beyond those caused by man.The question is:Which natural cause has most effect on the weather? One possibility is the variable behavior of the sun.Astronomers at one research station have studied the hot spots and 'cold' spots (that is, the ly less hot spots)on the sun.As the sun rotates ,every 27.5 days,it presents hotter or colder faces to the earth,and different aspects to different parts of the earth.This seems to have a considerable effect on the distribution of the earth atmospheric pressure,and consequently on wind circulation.The sun is also changeable over a long term:its heat output goes up and down in cycles,the latest trend being downward. ' Scientists are now finding shared relations between models of solar weather interactions and the actual climate over many thousands of years,including the last ice Age.The problem is that the models are predicting that the world should be entering a new Ice Age and it is not.One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia of the earth's climate.If this is right, the warming effect of carbon dioxide might thus be serving as a useful opposed balance to the sun's fading heat.
Question: It can be concluded that a concentration of carbon dioxide in the atmosphere would_.
Options: (A) mean a warming-up in the Arctic (B) raise the temperature of the earth's surface (C) prevent the sun's rays from reaching the earth's surface (D) explain the cause of great changes in the climate in the northern hemisphere

SOLUTION: B

PROBLEM: Article: Most of the news in the newspapers is bad but sometimes there is a story with good news. This is one of those stories. Millions of people around the world suffer from AIDS, malaria, tuberculosis, and other serious diseases. There are medicines to treat these diseases but for people in poor countries, these medicines are too expensive to buy. When a pharmaceutical company produces a new medicine, they receive a special license called a _ This license means that the new medicine or drug is protected for a period of 20 years. The company that produced the drug can fix the price of the drug and no other company is allowed to produce the same drug or a copy of the drug for 20 years. At the moment, these patents operate all over the world, both in rich countries and in poor countries. The drugs companies say that they need patents so that they can get the money to pay for research to find new drugs and medicines. In rich countries people usually have enough money to pay for these drugs but in poor countries people can't afford to buy them and cannot treat diseases like AIDS and malaria. Last month, however, a group of experts published a report which says that patents are very bad for poor countries. The report says that drug companies do not want to find new medicines for diseases of poor people in poor countries. It says that poor countries should be allowed to buy cheap drugs without patents from other countries. The authors of the report were lawyers, scientists and a senior director from the drug company Pfizer. Of course, the pharmaceuticals industry doesn't agree with the report, "We need patents so that we can develop new medicines to fight disease both in the developed and developing world," said a spokesman. But the report is the first sign that there might be a change in the patent system. This change could save millions of lives in the world's poorest countries. This really is good news.
Question: Why are medicines expensive for people in poor countries?
Options: (A) They are protected by patents. (B) They are produced in rich countries. (C) They are imported. (D) They can cure the deadly diseases.

SOLUTION:
A