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问题 单项选择题

作为小儿髋关节摄片，哪一项技术措施是不正确的

A．两侧髋关节应在一张胶片上同时摄片

B．对生殖腺要进行防护

C．两侧髋关节及股骨的位置一定要对称

D．应使用锐利度较高的低速增感屏

E．肢体左右铅号标记要正确

答案

参考答案：D

解析：使用锐利度较高的低速增感屏， X线剂量要加大，不利于X线的防护。

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单项选择题

Since life began eons ago, thousands of creatures have come and gone. Some, such as the dinosaurs, became extinct due to naturally changing ecologic conditions. More recent threats to life forms are humans and their activities. Man has drained marshes, burned prairies, dammed and diverted rivers. Some of the more recent casualties of man’s expansion have been the dodo, great auk, passenger pigeon, Irish elk, and Steller’s sea cow. Sadly, we can no longer attribute the increasing decline in our wild animals and plant species to "natural" processes. Many species are dying out because of exploitation, habitat alteration or destruction, pollution, or the introduction of new species of plants and animals to an area. As mandated by Congress, protecting endangered species, and restoring them to the point where their existence is no longer jeopardized, is the primary objective of the U.S. Fish and Wilidlife Service’s Endangered Species Program.

Which of the following has become extinct due to man’s destruction

A．African elephant

B．Irish elk

C．Giant panda

D．White Bengal
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