E Twenty years ago, most experts believed that differences in how boys and girls behaved were mainly due to differences in how they were treated by their parents, teachers, and friends. It’s hard to cling to that belief today. Recent research has shown that there are biological differences between boys and girls. Understanding these differences is important in raising and educating children. For example, girls are born with more sensitive hearing than boys, and the difference increases as kids grow up. So when a grown man speaks to a girl in what he thinks is a normal voice, she may hear it as yelling. Conversely (反过来), boys who appear to be inattentive in class may just be sitting too far away too hear the teacher. Likewise, girls are better in their expression of feelings. Studies reveal that negative emotions are seated in an area of the brain called the amygdala. Girls develop all early connection between this area and the cerebral cortex (大脑皮层), enabling them to talk about their feelings. In boys these links develop later. So if you ask a troubled adolescent boy to tell you what his feelings are, he often cannot say much. Dr. Sax, an advocate of single-sex education, points out that keeping boys and girls separate in the classroom has yielded striking educational, social, and interpersonal benefits. Therefore, parents and teachers should try to recognize, understand, and make use of the biological differences that make a girl a girl, and a boy a boy. 67．What is the main idea of the passage? A. Boys tend to pay less attention in class than girls. B. Girls are better than boys in their ability to detect sounds. C. Boys and girls behave differently because of biological differences. D. Single-sex schools are not good because they keep boys and girls separate. 68．Why do girls express negative feelings better than boys? A. Girls are more emotional than boys. B. Girls have more brain cells than boys. C. The amygdala is located in different areas of the brain for boys and girls. D. The links between certain parts of the brain develop earlier in girls than in boys. 69．Which of the following does the author believe? A. Girls need more training in communication. B. Boys and girls should be educated in different ways. C. Parents should pay more attention to boys. D. Sex differences should be ignored in education。 70．What does the phase “cling to” in the first paragraph mean? A. maintain               B. abandon                         C. evaluate          D. challenge