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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions
In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists’ predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves arc not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hypothesis is a leap into the unknown. It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories.
Which of the following is the main subject of the passage?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions
In developing countries, where three fourths of the world's population live, sixty percent of the people who can’t read and write are women. Being illiterate doesn’t mean they are not intelligent. It does mean it is difficult for them to change their lives. They produce more than half of the food. In Africa eighty percent of all agricultural work is done by women. There are many programs to help poor countries develop their agriculture. However, for years, these programs provided money and training for men. In parts of Africa, this is a typical day for a village woman. At 4:45 a.m, she gets up, washes and eats. It takes her a half hour to walk to the fields, and she works there until 3:00 p.m. She collects firewood and gets home at 4:00. She spends the next hour and a half preparing food to cook. Then she collects water for another hour. From 6:30 to 8:30 she cooks. After dinner, she spends an hour washing the dishes and her children. She goes to bed at 9:30 p.m. International organizations and programs run by developed nations are starting to help women, as well as men, improve their agricultural production. Governments have already passed some laws affecting women because of the UN Decade for Women. The UN report will affect the changes now happening in the family and society.
What does the word "run" in the last paragraph mean?