人类对金属的开发和利用是循序渐进的。 (1)青铜器是人类较早使用的金属制品。西汉

题型:填空题

问题:

人类对金属的开发和利用是循序渐进的。

(1)青铜器是人类较早使用的金属制品。西汉时期,人们主要采用“湿法冶金”。如将铁浸入硫酸铜溶液中,该反应的化学方程式为         

(2)随着技术的不断进步,人们能利用还原剂从金属的氧化物中将其还原出来。例如,

高炉炼铁所涉及的物质转化过程如下:

    

其中,物质A为   (填化学式),A与赤铁矿中的氧化铁反应的化学方程式为   

(3)每年因为腐蚀(如铁生锈)而报废的金属相当于年产量的20%~40%,人们采用多

种方法防止金属腐蚀。例如,将清洗后的铁锅擦干后存放可以防止铁锅生锈,其原

因是         

(4)铝的金属活动性比铁         (填“强”或“弱”),但铝制品却具有比较好的抗腐

蚀性能,其原因是         (用化学方程式说明)。

考点:金属的锈蚀与防护金属的回收利用金属的冶炼(铁的冶炼)
题型:填空题

A lift is wonderful. It is really only a small room. Rooms usually stay in one place. Lifts travel up and down all day long.

Sometimes a worker stands in the lift. He or she operates it up and down. In modern lifts there is no worker. The people walk in. They know what floor they want. They push a button and the lift goes to that floor. It is all very fast and easy.

Lifts are very important to us. Why? Think about a tall building. Maybe it has twenty floors. Maybe it has fifty or more. Who can walk up all the stairs? Maybe people can climb them one time. Can someone climb thirty floors to an office every day? Can small children walk up to their room on the twenty-fourth floor? Can their mother and father carry food up all those stairs? Of course not.

We can have high buildings because we have lifts. We could not have all the beautiful tall buildings in the world without lifts. They are really wonderful.

小题1:Which of the following is true?

A.A modern lift has no buttons.

B.A modern lift has a worker to operate it.

C.A modern lift can go up and down with no worker in it.

D.A modern lift knows what floor people want.小题2:If you want to go to the floor you want, you_______.

A.ask for help

B.open the door of the lift

C.ring the bell

D.push the right button小题3:Why do people have to use lifts? Because________.

A.they have tall buildings

B.they can't walk up and down

C.old people and children need them

D.lifts are wonderful

题型:填空题

掌指关节屈曲的正常活动度为()。

A.0°~60°

B.0°~70°

C.0°~80°

D.0°~90°

E.0°~100°

题型:填空题

根据反垄断法律制度的规定,在经营者集中附加限制性条件批准制度中,剥离业务的买方应当符合的要求有()。

A.独立于参与集中的经营者

B.拥有必要的资源、能力并有意愿使用剥离业务参与市场竞争

C.取得其他监管机构的批准

D.优先向参与集中的经营者融资购买剥离业务

题型:填空题

某拟建场地存在地裂缝,在地裂缝的下盘,建筑物在平面布置时应距离地裂缝( )。

A.5.0m

B.大于5.0m

C.7.0m

D.大于7.0m

题型:填空题

筋骨损伤时,可以通过保健按摩促进局部气血运行,消肿祛瘀,改善局部营养,促进新陈代谢,从而起到()的作用。

A、温暖经络

B、温暖筋骨

C、滑利关节

D、消炎抗菌

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