问题 选择题

有些化学反应不仅与反应物种类有关,还与反应条件(反应温度、反应物浓度)或反应物物质的量的比值有关,下列反应中与反应条件(反应温度、反应物浓度)、反应物物质的量的比值无关的是(  )

A.Fe粉与Cl2

B.CO2与Ca(OH)2溶液

C.Zn与H2SO4

D.Na2CO3与H2SO4溶液

答案

A、铁在氯气中燃烧,无论铁是否过量,产物都是氯化铁,故A正确;

B、CO2与Ca(OH)2溶液反应,当CO2少量时生成碳酸钙,CO2过量时生成碳酸氢钙,故B错误;

C、Zn与浓H2SO4反应生成二氧化硫,和稀H2SO4反应生成氢气,所以与浓度有关,故C错误;

D、Na2CO3与H2SO4溶液反应,硫酸少量生成NaHCO3,硫酸过量生成CO2,故D错误;

故选A.

阅读理解

阅读理解

     Easter(复活节) is still a great day for worship, randy in baskets and running around the yard finding

eggs, but every year it gets quite a bit worse for bunnies.

     And no, not because the kids like to pull their ears. The culprit is climate change, and some

researchers found that rising temperatures arc having harmful effects on at least five species of rabbit in

the US.

     Take the Lower Keys March rabbit, for instance. An endangered species that lives in the Lower

Florida Keys, this species of cottontail is a great swimmer - it lives on the islands! - but it is already

severely affected by development and now by rising levels. According to the Center for Biological

Diversity, an ocean level rise of only 0. 6 meters will send these guys jumping to higher ground and a

0.9-meter rise would wipe out their habitat (栖息地) completely.

     The snowshoe hare, on the other hand, has a color issue. Most of these rabbits change their fur color

from white in the wintertime to brown in the summer, each designed to give them better cover from

predators(捕食者).  As the number of days with snow decreases all across the country, however, more

and more bunnies arc being left in white fur during brown dirt days of both fall and spring, making them

an easier mark for predators. Researchers know that the color change is controlled by the number of

hours of sunlight, but whether the rabbit will be able to adapt quick enough to survive is a big question.

The National Wildlife   Federation has reported that hunters have noticed their numbers are already

markedly down.

     American pikas or rock rabbits, a relative of rabbits and hares, might be the firs' of these species to

go extinct due to climate change. About 7-8 inches long, pikas live high in the cool, damp mountains

west of the Rocky Mountains. As global temperatures rise, they would naturally migrate (迁徙) to higher

ground - but they already occupy the mountaintops. They can't go any higher. The National Wildlife

Federation reports that they might not be able to stand the new temperatures as their habitat beats up.

     The volcano rabbit has the same problem. These rabbits live on the slopes of volcanoes in Mexico,

and recent studies have shown that the lower range of their habitat has already shifted upward about

700 meters, but there are not suitable plants for them to move higher, so they are stuck in the middle.

Scientists are concerned about their populations.

     Native to the US, pygmy rabbits weigh less than 1 pound and live in the American West. They are

believed to be the smallest rabbits in the world. Their habitats have been destroyed by development.

Several populations, such as the Columbia Basin pygmy, almost went extinct and were saved by zoo

breeding programs. Pygmy rabbits also rely on winter cover by digging tunnels through the snow to

escape predators, but lesser snowfall is leaving them exposed.

      All of this gives new meaning to dressing up in a giant bunny costume this Easter.

1 The writer mentions Easter at the beginning of the passage in order to_______.

A. show the importance of Easter Day

B. introduce the issue about bunnies

C. remind people of Easter traditions  

D. discuss the relationship between Easter and bunnies

2. The word "culprit" ( Paragraph 2) is closest in meaning to______.

A. criminal

B. judge

C. victim

D. producer

3.According to the passage, some rabbits can now be easily Uncovered by predators because they___.

A. are exposed lo more skillful hunters

B. have moved to habitats with fewer plants

C. haven't adapted themselves to climate change

D. can't change their fur color into white in the fall and the spring

4. The problem faced by volcano rabbets and rock rabbits is that________.

A. both are affected by 1ess snow

B. both are affected by rising sea levels

C neither can find enough food 

D. neither can migrate to higher places

5 Which best describes the writer's tone in the postage?

A. Approving.

B. Concerned.

C. Enthusiastic.

D. Doubtful.

单项选择题