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问题 多项选择题

热塑性塑料件特点（）

A、反复加热而变软，其外观及化学成分并不发生变化

B、冷却后即变硬，可用塑料焊机焊接

C、在受到热、催化剂或紫外线的作用后会产生化学变化

D、再加热和使用催化剂也不会使其变形，其无法焊接

答案

参考答案：A, B, C, D

多项选择题 案例分析题

患者女性，49岁，已婚。因月经量增多6个月入院。于入院前10个月出现闭经达4个月。6个月前开始月经复潮，经期每次10天，量较前明显增多，周期15天。既往月经正常。生育史1-0-1-1。体胖。妇查： * * 见少量暗红色血迹，宫颈口闭，光滑。子宫体正常大小，活动度好。双侧附件正常。

提示：该病人术后2年来诊。诉说近2月来外阴搔痒，灼痛．白带多．色黄。频发膀胱炎。还应询问哪些有关症状（）

A.潮红.潮热.出汗

B.烦躁易怒，抑郁多虑

C.疲乏.关节痛

D.心前区有无不适感.心悸

E.大便秘结

F.血压波动
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单项选择题

"Sesame Street" has been called "the longest street in the world". That is because the television program by that name can now be seen in so many parts of the world. That program became one of American’s exports soon after it went on the air in New York in 1969.
In the United States more than six million children watch the program regularly. The viewers include more than half the nation’s pre-school children, from every kind of economic, racial, and geographical group.
Although some educators object to certain elements in the program, parents praise it highly. Many teachers also consider it a great help, though some teachers find that problems arise when first graders who have learned from "Sesame Street" are in the same class with children who have not watched the program.
Tests have shown that children from all racial, geographical, and economic backgrounds have benefited from watching it. Those who watch it five times a week learn more than occasional viewers. In the US the program is shown at different hours during the week in order to increase the number of children who can watch it regularly.
The programs all use songs, stories, jokes, and pictures to give children a basic understanding of numbers, letters and human relationships. But there are some differences. For example, the Spanish program, produced in Mexico City, devotes more time to teaching whole words than to teaching separate letters.
Why has "Sesame Street" been so much more successful than other children’s shows Many reasons have been suggested. People mention the educational theories of its creators, the support by the government and private businesses, and the skillful use of a variety of TV tricks. Perhaps an equally important reason is that mothers watch it along with their children. This is partly because famous adult stars often appear on it. But the best reason for the success of the program may be that it makes every child watching feel able to learn. The child finds himself learning, and he wants to learn more.

What is special about the program

A. It offers great fun.
B. It makes children feel able to learn.
C. It is shown at different hours during the week.
D. Children learn and enjoy themselves while watching.
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