汽车发动机在启动前,检查冷却液液量应()A、在下限之下 B、在散热器储水量的70%

题型:单项选择题

问题:

汽车发动机在启动前,检查冷却液液量应()

A、在下限之下

B、在散热器储水量的70%

C、不需要检查

D、在溢流箱上限(MAX)和下限(MIN)之间

考点:汽车驾驶员考试汽车驾驶员初级工考试汽车驾驶员初级工考试题库
题型:单项选择题

渐变工具提供了线性渐变、()、()、()和菱形渐变5种渐变方式。

题型:单项选择题

执行下面的程序后,a的值为
main()
int a,b;
for(a=1,b=1;a<=100;a++)
if(b>=20)break;
if(b%3==1)
b+=3;
continue;
b-=5;

A.7

B.8

C.9

D.10

题型:单项选择题

黄铁矿的主要成分是FeS2。测定黄铁矿中FeS2含量的两种方法如下图所示

已知:

①王水是由1体积的浓硝酸(ρ=1.42g·cm-3)和3体积的浓盐酸(ρ=1.19g·cm-3)混合而成的。

②黄铁矿和王水反应的方程式为FeS2+5HNO3+3HCl=FeCl3+2H2SO4+5NO↑+2H2O

请回答下列问题:

(1)简述实验室配制王水的操作过程___________________________。

(2)方法一中过滤、洗涤、灼烧都用到的仪器是_______________。

(3)方法二中要判断BaCl2溶液是否过量,可向滤液中加入X溶液,X可以是_______(填代号)

A.NaOH B.BaCl2 C.HCl D.Na2SO4

(4)实验室利用下列装置和试剂制取少量氯化氢气体

试剂:①浓硫酸  ②浓盐酸  ③食盐固体 

若选用试剂①②,则宜选择的装置是____________。若选用试剂①③,则应选择的装置是___________(填代号,下同);推测发生反应的化学方程式为____________________;

(5)方法一中,灼烧时发生反应的化学反应方程式为_____________________;已知称取黄铁矿样品的质量为1.50g,称得灼烧后固体的质量为0.4g,不考虑操作误差,则该矿石中FeS2的质量分数是______。

题型:单项选择题

Some years ago industries had more freedom than they have now,and they did not need to be as careful as they must today. They did not need to worry a lot about the safety of the new products that they developed. They did not have to pay much attention to the health and safety of the people who worked for them. Often new products were dangerous for the people who used them; often conditions in the work place had very bad effects on the health of the workers.

Of course sometimes there were real disasters which attracted the attention of governments and which showed the need for changes. Also scientists who were doing research into the health of workers sometimes produced information which governments could not ignore. At such times, there were inquiries into the causes of the disasters or the problems. New safety rules were often introduced as a result of these inquiries; however, the new rules came too late to protect the people who died or who became seriously ill.

Today many governments have special departments which protect customers and workers. In the U.S., for example, there is a department which tests new airplanes and gives warnings about possible problems. It also makes the rules that aircraft producers must follow. Another department controls the foods and drugs that companies sell. A third department looks at the places where people work, and then reports any companies that are breaking the laws which protect the health and safety of workers. Of course, new government departments and new laws cannot prevent every accident or illness, but they are having some good results. Our work places are safer and cleaner than before. The planes and cars which we use for travel are better. Producers are thinking more about the safety and health of the people who buy and use their products.

51. The main topic of the passage is ______.

A. conditions in the work place            B. the freedom of industries in the past

C. changes in industrial production       D. the safety and health of workers and customers

52. It can be inferred from the passage that in the past ______.

A. workers often got ill because of the poor working conditions

B. companies were free to put out any products they wanted to

C. many people were killed by dangerous products

D. industries were as careful in management as they are today

53. It is implied in the passage that ______.

A. governments and companies had different opinions about the safety of products

B. in the past no safety laws were introduced by governments

C. government officials often did not listen to scientists

D. governments paid no attention to the safety of products at all

54. From the passage, we know that some years ago safety rules ______.

A. were put forward due to scientists’ recommendations

B. came into being as a result of the workers’ demands

C. were introduced because quite a number of people were killed or seriously injured

D. were effective enough to protect workers and customers

55. The special departments protect customers and workers in many ways EXCEPT by ______.

A. testing new products                       B. controlling the sale of products

C. designing new products                   D. inspecting work places

题型:单项选择题

CiTRANS640设备2M盘E1K1可以插在哪些槽位()。

A.10

B.11

C.18

D.19

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