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

问题:

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

考点:核医学与技术(医学高级)核医学与技术综合复习题核医学与技术综合复习题题库
题型:单项选择题

阅读理解。

     F1 is a very fast car race. It is one of the most popular sports in the world. The drivers go at over

300 kilometers an hour every race. But F1 cars didn't always go so fast.

     In 1895, the first F1 race began in France. During that race, it took the drivers 48 hours to finish

580 kilometers. In 1901, the best drivers had an average (平均) speed of 100 kilometers an hour.

Modern grand prix (奖品) F1 racing began in 1950 in Britain. Grand prix is French. It means "large

prize". Today, 12 teams and 24 drivers race to get points. There are races at different tracks (路线) all

over the world from March to October every year. There are also F2 and F3 racing. But the cars are

slower and less high-tech.

    During a F1 race, drivers have to make several stops to change tyres(轮胎) and put more petrol in

their cars. A team of people do these tasks together to make the stops short. Some people lift the car

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

and a different person cleans the driver's helmet. One more person talks to the driver about how to win.

It's amazing that all those people finish it in just a few seconds!

     During 100-meter races, people count the athletes' speed by 1/100th (0. 01) of a second, for example

10.81 seconds. In the world of car racing, however, the race has to be timed to 1/1,000th(0. 001) of a

second. That is 50 times faster than the time for a blink (眨眼).

     F1 cars look very colorful. First, cars of different teams have different colors. Then there are a lot

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

题型:单项选择题

2009年入春以来,甲型H1N1在全球流行,在疾病防治、疫情控制等方面起到重要作用的国际组织是[ ]

A.世界贸易组织

B.国际奥委会

C.世界卫生组织

D.亚太经合组织

题型:单项选择题

在下列经脉中,向上循脊柱的经脉是()。

A.任脉

B.督脉

C.膀胱经

D.肺经

E.心经

题型:单项选择题

燥咳的特点为()

A.咳声紧闷

B.咳声清脆

C.咳声重浊

D.咳声低微

E.咳声如犬吠

题型:单项选择题

从法律角度看,保险人与投保人通过签定保险合同所建立起来的保险法律关系属于______。

A.行政法律关系
B.刑事法律关系
C.民事法律关系
D.国家法律关系

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