问题 单项选择题 共用题干题

[复合型非选择题]患者女,55岁,因“反复发作性头晕1个月”来诊。高血压病史15年,未规律服用降压药;因冠状动脉狭窄做冠状动脉支架术后1年;否认糖尿病、高血脂病史。吸烟10~20支/d×20年。查体:双侧桡动脉搏动不对称,左侧相对减弱;双上肢血压不对称,右侧165/100mmHg,左侧100/60mmHg。

不能发现该动脉狭窄或闭塞的检查是()

A.颈动脉超声

B.经颅多普勒(TCD.超声

C.颅脑MRI

D.血管造影(DSA.

E.颅脑+颈部磁共振血管造影

答案

参考答案:C

单项选择题 A1/A2型题
单项选择题

The sun today is a yellow dwarf star. It is fueled by thermonuclear reactions near its center that convert hydrogen to helium. The sun has existed in its present state for about 4 billion, 600 million years and is thousands of times larger than the Earth.
By studying other stars, astronomers can predict what the rest of the sun’s life will be like. About 5 billion years from now, the core of the sun will shrink and become hotter. The surface temperature will fail. The higher temperature of the center will increase the rate of thermonuclear reactions. The outer regions of the sun will expand approximately 35 million miles, about the distance to mercury, which is the closest planet to the sun. The sun will then be a red giant star. Temperatures on the earth will become too hot for life to exist.
Once the sun has used up its thermonuclear energy as a red giant, it will begin to shrink. After it shrinks to the size of the earth, it will become a white dwarf star. The sun may throw off huge amounts of gases in violent eruptions called nova explosions as it changes from a red giant to a white dwarf.
After billions of years as a white dwarf, the Sun will have used up all its fuel and will have lost its heat. Such a star is called a black dwarf. After the Sun has become a black dwarf, the earth will be dark and cold. If any atmosphere remains there, it will have frozen onto the earth’s surface.

What is the primary purpose of this passage

A.To alert people to the dangers posed by the sun.
B.To discuss conditions on earth in the far future.
C.To present a theory about red giant stars.
D.To describe changes that the sun will go through.