问题 单项选择题

有关椎间盘变性,正确的是()

A、T2加权像最为敏感 

B、T1加权像显示较差 

C、变性的椎间盘可出现真空现象 

D、变性的椎间盘可钙化 

E、以上均是 

答案

参考答案:E

阅读理解

In the past 300 years, more than 130 species of animals have become extinct. One of these extinct species is the passenger pigeon(旅鸽). At one time there were millions of these birds in North America, but now there are none. The last one died in the Cincinnati Zoo in 1914. Another extinct animal is the cape lion(西非狮). The animal has been extinct since 1860.

What cause animals to become extinct? Too much hunting is one cause; pollution is another.

Governments around the world have begun to protect wild animals in danger. In the United States, the US Fish and Wildlife Service is responsible for(承担义务)endangered animals. It has listed nearly 200 species of endangered animals in North America.

小题1:The underlined word “extinct” in the first sentence probably means “         ”.

A.ill

B.dying out

C.becoming

D.changing小题2:There were many cape lions in North America          .

A.last century

B.in the twentieth century

C.more than one hundred years ago

D.in 1914小题3:       isn’t the reason for the extinction of wild animals in North America.

A.The pollution

B.Too much killing

C.Too much hunting

D.The war小题4:Three are        species of wild animals in danger listed by the US Fish and Wildlife.

A.less than 130

B.about 200

C.over 300

D.nearly 300小题5:The best title of this passage should be “       ”.

A.A sad story

B.Endangered animals in North America

C.Wild animals become extinct

D.The US Fish and Wildlife Service

填空题