问题 选择题

下列观点正确的是

A.某单质固体能导电,其单质一定是金属

B.某化合物的水溶液能导电,该化合物一定是电解质

C.某化合物的熔融状态能导电,该化合物中一定有离子键

D.某纯净物在常温下为气体,则组成该物质的微粒一定含有共价键

答案

答案:C

题目分析:A、某单质固体能导电,其单质不一定是金属,例如硅、石墨等,A不正确;B、某化合物的水溶液能导电,该化合物不一定是电解质,例如CO2等的水溶液也能达到,但二氧化碳是非电解质,B不正确;C、共价键在熔融时不断裂,则某化合物的熔融状态能导电,该化合物中一定有离子键,C正确;D、某纯净物在常温下为气体,则组成该物质的微粒不一定含有共价键,例如稀有气体,D不正确,答案选C。

阅读理解

第二部分:阅读理解(共两节,满分40分)

第一节(共15题;每小题2分,满分30分)

阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项,并在答题卡上将该项涂黑。

If you are looking for a new pet, don’t even think about Komodo dragons, which are the largest lizards and can grow to be 10 feet long and weigh more than 300 pounds. Komodo dragons run fast and eat almost any kind of meat, including dead or live animals, other Komodo dragons and people. “These things are powerful killing machines,” says Bryan Fry, a biologist.

If those reasons aren’t good enough, consider the bite of a Komodo dragon. According to a new study, it may kill prey like snakes by injecting venom. This chemical, according to Fry and his team of scientists at the University of Melbourne in Australia, can cause shock in the unlucky victim. A person or animal goes into shock when the body can’t offer enough blood to organs to keep functioning. As a result, the body starts to shut down.

Scientists have only recently begun to understand why a Komodo dragon is so deadly. Some people used to believe that a Komodo dragon’s bite contained bacteria from the mouth that would cause a severe infection in the victim’s blood. The infection would finally kill the animal. Fry says that after being bitten by a Komodo dragon, animal usually die quickly.

After more studies, Fry and his team found that Komodo dragon venom contained some of the same ingredients as snake venom. These ingredients thin the blood and cause blood vessels to become larger. To test the venom, the scientists injected rats with it and observed that the rats became still.

Fry’s work shows that Komodo dragons kill their prey with venom, and not by bacteria — and gives us another reason why we should avoid coming across them. That is easy to do, since they live on a few islands in the tropical country of Indonesia.

41. From the passage we can learn that ______.

A. Komodo dragons live on a few islands of India

B. a Komodo dragon weighs more than 300 kilograms

C. a Komodo dragon is more than eleven feet long

D. nobody dares to keep a Komodo dragon as a pet

42. The underlined word “venom” in Paragraph 2 probably means ______.

A. the chemical that does no harm  

B. a kind of way that kills its enemy

C. a kind of poisonous liquid of some animals 

D. the gas which could cause death

43. Why does a victim get into shock after being injected?

A. He or it is too afraid to move about.

B. His or its organs can’t get enough blood.

C. His or its body was hurt and shuts down.

D. He or it is bitten and loses much blood.

44. Komodo dragons can’t easily hurt us because ______.

A. they are afraid of human beings

B. the venom in them is not so powerful

C. our blood can make them close to us

D. they only inhabit a few islands in Indonesia

单项选择题