2012年3月22日是第二十届“世界水日”.水与人类的生活和生产密切相关. (1

题型:问答题

问题:

2012年3月22日是第二十届“世界水日”.水与人类的生活和生产密切相关.

(1)节约用水、防止水污染应成为我们的自觉行为.下列有关叙述中不正确的是______.

A.生活中养成良好的用水习惯,节约用水

B.工业废水经过处理达标后再排放

C.水体污染会危害人体健康

D.大量使用农药、化肥,不会造成水体污染

(2)水是最常见的溶剂,将少量下列物质分别加入水中,不能形成溶液的是______.

A.植物油       B.食盐       C.蔗糖     D.高锰酸钾

(3)区分软水和硬水常用的物质是______.

(4)自来水厂在净化水时,常加入活性炭以清除水中异色、异味,其净化原理是利用活性炭的______作用;

(5)如图所示是水的电解实验,试管1中收集的气体是______,试管2中收集的气体可用______来检验.

(6)下列反应中,不能用来确定水由氢、氧元素组成的是______.

A.H2和O2反应    B.电解水   C.H2和Cl2反应.

考点:水污染与防治电解水实验硬水和软水溶液的定义、组成及特征
题型:问答题
已知f(x),g(x)满f(5)=2,f'(5)=3,g(5)=1,g'(5)=2,则函数y=
f(x)+2
g(x)
的图象在x=5处的切线方程为______.
题型:问答题

根据短文内容,判断下列句子的正误,正确的用“T”,错误的用“F”。(每小题1分,共5分)

There are many wetlands (湿地) in China and some of them have become the world's important wetlands.

The Chinese Yellow Sea Wetlands are among them. They are in Yancheng, Jiangsu Province. They are home for many different kinds of birds and animals. The world's largest Milu Deer Nature Reserve (自然保护区) is in them. More than 700 Milu deer live freely there. There are not many red-Crowned cranes in the world, but every winter you can see some in the red-Crowned Nature Reserve in the Yellow Sea Wetlands.

The temperature in the wetlands is usually neither too high nor too low. There is a lot of rain and sunshine, too. They are really good places for wildlife (野生动物). Offering food and home for some special kinds of animals and birds is not the only reason why we need to protect wetlands. Wetlands are important because they also prevent flood. But some people want to change the wetlands to make more space for farms and buildings. This means there will be less and less space for wildlife.

Luckily, more and more people are beginning to realize the importance of wetlands and wildlife. Every year, on February 2nd, many activities are held to tell people more about wetlands. 

小题1:The Chinese Yellow Sea Wetlands are in the west of China.

小题2:Usually the weather in the wetlands is pleasant.

小题3:February 2nd is the world's wetlands Day.

小题4:We must protect wetlands only because they can offer food to the animals and birds.

小题5:Wetlands are valuable resources of land on the earth. 

题型:问答题
计算:-32-(-2)3×(-4)÷(-
1
4
)
题型:问答题

人机功能匹配要在功能分析基础上,依据人机特性进行分配。下列任务中,适合机器完成的是( )。

A.维修

B.程序的编排

C.高价运算

D.故障处理

题型:问答题

粉末显微观察,可见骨组织构造的中药是

A.龙骨

B.赤石脂

C.玛瑙

D.琥珀

E.煤珀

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