问题 问答题

小东发现骑摩托车的人到了寒冬时节常常车座上垫上一块海绵做的垫子,而到了夏天常常车座上垫上一块竹子做的垫子.骑车人为什么要这么做呢?小东猜想:这是不是因为海绵和竹子的物理特性有什么不同呢?

(1)请你根据情景提出合理的猜想.

(2)设计一个实验检验你的猜想.要求写出实验方法.

答案

(1)由冬夏温度的差异,而选用不同材料.引出猜想:海绵比竹子的保温性能更好一些.

(2)实验设计:用厚度相同的竹片与海绵分别包住成有相同温度相同质量的热水的烧杯,烧杯中各放有一支温度计.将它们放在同一房间里,经过一段时间后,比较温度计的示数,来确定那种材料保温性能更好一些.

故本题的答案为:

(1)猜想:海绵比竹子的保温性能更好一些.

(2)实验方法:A,用厚度相同的竹片与海绵分别包住成有相同温度相同质量的热水的烧杯,烧杯中各放有一支温度计.将它们放在同一房间里.

B,每经过3分钟后,读出温度计的示数,记录下来填入表格.

(3)根据记录的数据,比较那种材料保温性能更好一些.

单项选择题
阅读理解

Stepping into a pool of water is common enough, but who could ever imagine stepping into a pool of fish? In February of 1974, Bill Tapp, an Australian farmer, saw a rain of fish that covered his farm. How surprised he must have been when he heard many fish hitting against his roof!

   What caused this strange occurrence? This is a question that had long puzzled people who study fish. The answer turned out to be a combination of wind and storm.

  When it is spring in the northern part of the world, it is fall in Australia. Throughout the autumn season, terrible storms arise and rains flood the land. The strong winds sweep over Australia like huge vacuum cleaners, collecting seaweed, pieces of wood, and even schools of fish. Strong winds may carry these bits of nature for many miles before dropping them on fields, houses, and astonished people.

  Although they seem unusual, fish-falls occur quite frequently in Australia. When Bill Tapp was asked to describe the scene of fish, he remarked, “They look like millions of dead birds falling down.” His statement is not surprising. The wonders of the natural world are as common as rain. Nature, with its infinite wonders, can create waterfalls that flow upward and fish that fall out of the sky.

  56. What is this passage about?

  A. A sad story.             B. A rain of fish.

  C. Australia’s northern part.     D. The damage done by floods.

  57. Fish-falls occur in Australia_________ .

  A. quite often       B. on large farms

  C. only in winter     D. when the air is calm

  58. It is a known fact that ________.

  A. one should watch where one steps

  B. Bill Tapp is a scientist who studies farming

  C. the natural world can never create waterfalls that fall upward

  D. the seasons in the southern part are different from those in the northern part

 59. The word “infinite” is closest in meaning to _________.

  A. easy    B. difficult    C. countless    D. dangerous