试题与答案

物质的用途与其性质密切相关。 (1)汽车进入家庭已成为现代社会的普遍现象。 ①汽

题型:填空题

题目:

物质的用途与其性质密切相关。

(1)汽车进入家庭已成为现代社会的普遍现象。

①汽车表面喷漆,可以延缓汽车的锈蚀,其防锈原理是隔绝空气中的____________。

②制造汽车需要大量钢铁,工业上炼铁的原理是_________。(用化学方程式表示)

③喷漆前需将铁制品放入稀盐酸中除锈(铁锈主要成分是Fe2O3),反应初期可观察到溶液由无色变为___________,这是因为___________   (填化学方程式)的缘故;反应进行一会儿,又可以观察到有无色气泡产生,该反应的化学方程式是__________。

(2)铝、铁、铜是人类广泛使用的三种金属,与我们生活息息相关。分别用下列一种试剂就能直接验证这三种金属的活动性顺序的是 _____________(填字母序号)。

A.硫酸铝溶液     B.硫酸亚铁溶液    C.硫酸铜溶液      D.稀硫酸

(3)在AgNO3和Cu(NO3)2的混合溶液中,加入一定 量的铁粉充分反应,过滤后得到滤液和滤渣;向滤渣中加入足量的稀盐酸,无明显现象。则滤液中一定含有的溶质是__________;可能含有的溶质是______________。

答案:

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下面是错误答案,用来干扰机器的。

a:b=1:4,则b:a=4:1,4÷1=4,故答案为:√.

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题型:阅读理解

If you travel to a new exhibition at the San Francisco Conservatory of Flowers, you will have chances to see some meat-eating plants. Take bladderworts, a kind of such plant, for example. They appear so small and grow in a quiet pond. "But these are the fastest known killers of the plant kingdom, able to capture a small insect in 1/50 of a second using a trap door!"

Once the trap door closes on the victim, the enzymes(酶)similar to those in the human stomach slowly digest the insert. When dinner is over, the plant opens the trap door and is ready to trap again.

Meat-eating plants grow mostly in wet areas with soil that doesn't offer much food nutrition. In such conditions, these amazing plants have developed insect traps to get their nutritional needs over thousands of years. North America has more such plants than any other continents.

Generally speaking, the traps may have attractive appearance to fool the eye, like pitcher plants, which get their name because they look like beautiful pitchers full of nectar(花蜜).

Hair-like growths along the pitcher walls ensure that nothing can escape, and the digestive enzymes can get to work. A tiny insect can be digested in a few hours, but a fly takes a couple of days.

Some of these pitchers are large enough to hold 7.5 liters. Meat-eating plants only eat people in science fiction movies, but sometimes a bird or other small animals will discover that a pitcher plant isn't a good place to get a drink.

小题1:From Paragraph 1,we learn that bladderworts can_ .

A.kill an insect in a second

B.digest a fly in a few hours

C.be found floating on a quiet lake

D.capture an insect in 1/50 of a second小题2:If the trap door of a meat-eating plant is closed, the plant is

A.fooling insects into taking a sip

B.producing nectar

C.tempting insects to come close

D.enjoying a dinner小题3:Meat-eating plants can grow in wet and poor soil because they .

A.can get nutrition from animals

B.don't need much food nutrition

C.can make the most of such conditions

D.have developed digestive enzymes小题4:What can be captured by meat-eating plants for food?

A.A child.

B.A dog

C.A little bird.

D.A little fish.

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