MMA变成PMMA的条件是A.加入还原剂B.加入成形剂C.加入促进剂D.加入促凝剂E

题型:单项选择题

问题:

MMA变成PMMA的条件是

A.加入还原剂
B.加入成形剂
C.加入促进剂
D.加入促凝剂
E.以上均不是

考点:口腔医学技术(主管技师)口腔技师基础知识中级口腔医学主管技师基础知识
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国家制定对外政策的目的是()

A.实现国家的内外职能

B.实现社会团体的对外交往

C.实行侵略与扩张

D.实行国际主义

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请将人体器官与其生理功能用线段连接起来.

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NANJING, June 13,2009 (Xinhua) – China will see the longest total solar eclipse (日食) in 500 years on July 22, a scientist said Saturday.

The most important time of the total eclipse was expected to
begin from 9:00 a.m. to 9:38 a. m. (Beijing Time), said Wang
Sichao, a research fellow with the Nanjing – based Purple
Mountain Observatory under the Chinese Academy of Sciences.
“The total eclipse will l ast up to six minutes, which is the longest
one that can be seen in China in almost 500 years from 1814 to 2309,” Wang said.
He said viewers in parts of eleven provinces in China's southwestern, central-southern and eastern areas, such as Tibet, Hunan and Jiangsu, will be able to witness the total solar eclipse, while in most parts of Shanghai, viewers can see the spectacular phenomenon. For viewers in other provinces, including Beijing, they can observe a partial eclipse, he said.
A solar eclipse occurs when the moon is caught between the sun and the earth while each of them moves along their fixed orbits. In a total solar eclipse, the sun, the moon and the earth are directly aligned as the sun swings into the cone of shadow cast by the moon.
Wang said the next total solar eclipse that can be seen in China will fall on March 20 th, 2034.     "But it can only be seen remote provinces, such as Tibet and Qinghai. It cannot not be compared with the upcoming one -- in terms of duration and number of cities that can see the eclipse," he added. The last total solar eclipse visible in China took place on Aug. 1 last year. It was observed in northwest China and lasted two minutes in Yiwu County of northwestern Xinjiang Uygur Autonomous Region, the best place to see the phenomenon.
72.According to the report, the total eclipse on July the 22 nd will last         .
A.over a month                                                    B.about 38 minutes
C.about 6 minutes                                              D.less than 30 minutes
73.Viewers can possibly witness the total solar eclipse in            .
A.Liaoning                   B.Sichuan                    C.Beijing                      D.Xinjiang
74.When a total solar eclipse happens,          .
A.the moon goes into the shadow cast by the sun
B.the earth stays between the sun and the moon
C.the sun temporarily moves into the moon’s orbit
D.the sun is in a line with the moon and the earth
75.Which is the best title for this report?           .
A.China to witness longest total solar eclipse in 500 years
B.The most important total solar eclipse will favor China
C.The beginning time of the total solar eclipse is expected
D.China has been the best place to witness the solar eclipse
题型:单项选择题

下面有关眼镜的改进方案,哪些属于实用新型专利保护的客体

A.一种眼镜,其特征在于镜架由插件构成,并可自由拆装

B.一种眼镜,其特征在于镜架由一种新型材料制成

C.一种眼镜,其特征在于镜架上粘贴有北京奥运会标志

D.一种眼镜,其特征在于镜架经过高温处理

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按照国家有关规定,国家发展改革委员会对地方政府投资的项目,需要审批( )

A.项目建议书和可行性研究报告

B.资金使用计划报告

C.项目建议书

D.可行性研究报告

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