问题 填空题

判断正误:

(1)热胀是微粒变大了,冷缩是微粒变小了.______;

(2)100毫升的水和100毫升的酒精混合,总体积为200毫升.______;

(3)10克大豆和10克芝麻混合,总体积变小,说明微粒之间有空隙.______.

答案

(1)由于分子之间有间隔,物质受热时,分子之间的间隔变大了,物质的体积变大;遇冷时,分子之间的间隔变小了,物质的体积变小,故说法不正确;

(2)由于分子之间有间隔,当100毫升的水和100毫升的酒精混合时,水分子和酒精分子相互占据了空间,所以,总体积小于200毫升.故说法不正确;

(3)大豆和芝麻不是由微粒直接构成的,虽然10克大豆和10克芝麻混合,总体积变小,不能说明说明微粒之间有空隙,故说法不正确.

故答为:(1)不正确;(2)不正确;(3)不正确;

选择题
阅读理解

阅读理解。

     We have met the enemy and he is ours. We bought him at a pet shop. When monkey-pox, a disease usually

found in the African rain forest suddenly turns up in children in the American Midwest, it's hard not to wonder

of the disease that comes from foreign animals is homing in on human beings. "Most of the infections (感染)

we think of as human infections started in other animals" says Stephen Morse, director of the Center for Public

Health Preparedness at Columbia University.

     It's not just that we're going to where the animals are; we're also bringing them closer to us Popular foreign

pets have brought a whole new disease to this country. A strange illness killed Isaksen's pets and she now thinks

that keeping foreign pets is a bad idea. "I don't think it's fair to have them as pets when we have such a limited

knowledge of them" says Isaksen.

     "Laws allowing these animals to be brought in from deep forest areas without stricter control need changing"

says Peter Schantz. Monkey-pox may be the wake-up call Researchers believe infected animals may infect their

owners. We know very little about these new diseases. Anew bug (病毒) may be kind at first But it may develop

into something harmful (有害的). Monkey-pox doesn't look a major infectious disease. But is not impossible to

pass the disease from person to person.

1. We learn from Paragraph I that the per sold at the shop may _____.

A. come from Columbia

B. prevent us from being infected

C. enjoy being with children

D. suffer from monkey-pox

2. Why did Isaksen advise people not to have foreign pets?

A. They attack human beings

B. We need to study native animals

C. They can't live out of the rain forest

D. We do not know much about them yet

3. What does she phrase "the wake-up call" in paragraph 3 most probably mean?

A. a new disease

B. a clear warning

C. a dangerous animal

D. a morning call

4. The text suggests that in the future we _____.

A. may have to fight against more new diseases

B. may easily get infected by diseases from dogs

C. should not be allowed to have pets

D. should stop buying pests from Africa