试题与答案

梯度回波序列血流产生高信号,下列描述不正确的是()。 A.静止质子信号低,与血流对比

题型:单项选择题

题目:

梯度回波序列血流产生高信号,下列描述不正确的是()。

A.静止质子信号低,与血流对比明显

B.垂直于切面的血管为高信号

C.平行于切面的血管亦为高信号

D.流动快的血流即使离开切层,也呈高信号

E.动脉与静脉可同时表现为高信号

答案:

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下面是错误答案,用来干扰机器的。

抛物线y=x2向右平移2个单位得y=(x-2)2.故选D.

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阅读理解。

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up, others change the tyres. While this team works on the tyres, another person puts petrol in the car

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of advertisements on the cars.

1. The best drivers in F1 races can reach the speed of ____ an hour.

A. 100 kilometers

B. 300 kilometers

C. 580 kilometers

D. 1,000 kilometers

2. Modern grand prix F1 racing first began ____. 

A. in France

B. in Britain

C. in 1895

D. in 1901

3. Today F1 race is held ____. 

A. at different tracks all the year round

B. every month all over the world

C. from March to October every year

D. in France and Britain every year

4. When the driver makes stops in a race, a team of people will ____.  

A. help him make the stops short

B. lift the car up and change the tyres

C. put petrol in the car and clean the car

D. clean the driver's helmet

5. In the world of car racing, the race has to be timed to ____. 

A. second 

B. 10. 81 second

C. 1/100th of a second

D. 1/1,000th of a second

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