阅读理解。 If there is no difference in general intelligence (智力) between boys and girls, what can explain girls' poor performance in science and mathematics? It seems to be that their treatment at school is a direct cause. Mathematics and science are seen as subjects mainly for boys, and therefore, as girls become teenagers, they are less likely to take them. Interestingly, both boys and girls often regard the subjects for boys as more difficult. Yet it has been suggested that girls do not take mathematics courses, not because they are difficult, but for social reasons. Girls do not want to be in open competition with boys because they are afraid to appear less feminine (女性的) and attractive. However, if we examine the performance of boys and girls who have taken mathematics courses, there are still more high-achieving boys than there are girls. This difference appears to be world-wide. Biological explanations have been offered for this, but there are other explanations too. Perhaps the difference which comes out during the teenage years has its roots in much earlier experiences. From their first days in kindergarten, boys are enoouraged to work on their own and to complete tasks. Facts show that outstanding (杰出的) mathematicians and scientists have not had teachers who supplied answers. Besides, there can be little doubt that teachers of mathematics and science expect their boy students to do better at these subjects than their girl students. They even appear to encourage the difference between boys and girls. They spend more time with the boy students, giving them more time to answer questions and working harder to get correct answers from them. They are more likely to call on boys for answers and to allow them to take the lead in classroom discussion. They also praise boys more frequently. All of this seems to encourage boys to work harder in science and mathematics and to give them confidence (信心) that they are able to succeed. Such a way of teaching is not likely to encourage girls to take many mathematics and science courses, nor is it likely to support girls who do. When it comes to these subjects it seems certain that school widens the difference between boys and girls. 1. Girls are likely to think that _____. A. science courses are for both boys and girls B. science courses make them more popular C. science courses make them successful D. science courses are difficult for them 2. The text mainly discusses _____ reasons for the difference between boys and girls in scientific achievements. A. biological B. historical C. social D. personal 3. What are boys usually encouraged to do at school? A. To get help with their homework. B. To play the leading role in class. C. To work with girl students in class. D. To learn to take care of others . 4. What does the passage say about great mathematicians? A. Their teachers did not supply answers to them. B. They started learning mathematics at an earlier age. C. They showed mathematical abilities in their teenage years. D. Their success resulted from their strong interest in mathematics. 5. The author would probably agree that _____. A. boys and girls learn in the same way B. boys and girls are equal in general intelligence C. girls are more confident in themselves than before D. girls should take fewer science courses than boys