出生缺陷的预防分为三级预防，具体是哪些？

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

下列哪项不是结核性脑膜炎的CT表现（）

A.基底池密度增高

B.基底池增强

C.脑积水

D.凸面脑膜增强

E.脑膜不增强

自动挡汽车在陡坡行驶时使用"L"挡。

能发生糖异生的不包括()

A．甘油

B．氨基酸

C．乳酸

D．丙酮

E．丙酮酸

化肥污染通过食物严重影响人们的健康，因而被视为是农药的一种污染，尤其是大棚内栽种的蔬菜受到化肥污染较严重。中国农业科学院依据联合国粮农组织和世界卫生组织对食品硝酸盐(氮肥的分解物)摄入量的规定，提出了蔬菜卫生的评价标准：蔬菜中硝酸盐含量低于432mg/kg，允许生食；432～785mg/kg，不宜生食；785～1440mg/kg，生食和盐渍均不宜；1440～3100mg/kg，不允许熟食。 上海市近期一项对蔬菜的检测发现，大棚内叶类蔬菜硝酸盐超标率达51.5%，茄果类超标率达15.6%；而大田叶类蔬菜硝酸盐超标率为20.5%，茄果类则未检出。造成大棚内蔬菜硝酸盐含量积累高的主要因素有几方面但都与化肥的过量和不当施加有关系：大棚内蔬菜生产周期长，化肥投入水平比大田蔬菜高出50%以上；大棚封闭的环境条件，由于得不到雨水冲洗，土壤中硝酸盐容易积累含量升高；大棚内光照强度比大田弱，使蔬菜作物叶片中硝酸盐还原酶活力下降，导致硝酸盐积累加大等等。 下列选项中，( )对减少化肥对大棚蔬菜的污染作用不大。

A．氮肥深施并盖土

B．控制氮肥用量并早施肥

C．少用或不用化肥

D．加强外部光照