题干

在火车站或地铁站的站台上,离站台边缘1m左右的地方标有一条安全线,乘客必须站在安全线以外的地方候车,这是为什么呢?

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答:列车开来,人和列车间的空气流速增大,压强减小,外侧的空气流速不变,压强不变,所以人受到的外侧压强大于人和列车间的压强,容易把人推向列车,发生事故.


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任务型阅读
    In a society such as the United states or Canada, which has many national, religious, and cultural differences, people highly value individualism—the differences among people. Teachers place a lot of importance on the qualities that make each student special. The educational systems in these countries show these values. Students do not memorize information. Instead, they work individually and find answers themselves. There is often discussion in the classroom. At an early age, students learn to form their own ideas and opinions.
    In most Asian societies, by contrast, the people have the same language, history, and culture. Perhaps for this reason, the educational system in much of the Orient reflects society's belief in group goals and purposed rather than individualism. Children in China, Japan, and Korea often work together and help one another on assignments. In the classroom, the teaching methods are often very formal. The teacher lectures, and the students listen. There is not much discussion. Instead, the students recite rules or information that they have memorized.
    There are advantages and disadvantages to both of these systems of education. For example, one advantage to the system in Japan is that students there learn much more math and science than American students learn by the end of high school. They also study more hours each day and more days each year than North Americans do. The system is difficult, but it prepares students for a society that values discipline and self-control. There is, however, a disadvantage. Memorization is an important learning method in Japanese schools, yet many students say that after an exam, they forget much of the information that they have memorized.
    The advantage of the educational system in North American, on the other hand, is that students learn to think for themselves. The system prepares them for a society that values creative ideas. There is , however, a disadvantage. When students graduate from high school, they haven't memorized as many basic rules and facts as students in other countries have..
Students in the US and ____Students in China, Japan and Korean
What do they value?________ goals and purposes
Ways of studyworking individuallylisten to the teachers
forming their own  ideas and opinionsmemorizing and ____
a lot of discussion in the classroomnot much discussion
____Learning to think for themselveslearning much more math and ____ by the end of high ____
studying more hours each day and more days each year
good for a society that values ____ ideas.good for a society valuing ____ and self-control
disadvantagesstudents haven't memorized many basic rules and facts when before ____Information is forgotten easily