问题 实验题

图所示,某同学在做“探究平面镜成像特点”的实验时,在桌子上铺好一张大白纸,然后在中间画一横线,将一块玻璃板竖直沿此直线放好,取两段等长的蜡烛,将蜡烛A点燃放在玻璃板的前方,然后用另外一根蜡烛B在玻璃板的后方来回移动。

(1)调节蜡烛B的位置,直到                   时, B的位置即为A的像所在的位置。

(2)找到A的像的位置后,连结蜡烛A和蜡烛B所在的位置,发现该连线与玻璃板所在直线         ,两段蜡烛等长是为了比较像与物的           关系。

(3)若用平面镜代替玻璃板,上述实验         进行。(填 “能”或“不能”)

答案

(1)B与A的像完全重合 (2)垂直 大小  (3)不能

蜡烛B与蜡烛A的像只有完全重合才可以比较大小.观察发现连线与玻璃板所在直线垂直.因为平面镜不透明上述实验不能进行.

答案为:(1)蜡烛B与蜡烛A的像完全重合;

(2)垂直;大小

(3)不能

阅读理解

阅读理解。

     The famous scientist and thinker, Charles Darwin, was born on February 12, 1809. As a boy,

Charles liked to go for walks in the fields and forests, watching nature, and comparing what he saw

with everything he had read in science books. He also liked collecting very much. He collected many

things: birds, stones, and leaves.

     At sixteen Darwin was sent to Edinburgh University to become a doctor. But he was interested

in the history of nature.

     Then he was sent to study at Cambridge University. There he studied until 1831.

     Some time later he heard that the ship Beagle was going on a trip to South America and wanted a

scientist. His professor advised him to go. So when the Beagle left England in December 1831, Darwin

was on it.

     The expedition lasted almost five' years. Darwin saw many new plants and animals. He collected

all kinds of plants.

     In 1842 Darwin went to live in Kent, and there he continued his studies of change in nature. Darwin

understood that plants and animals are not always the same, and that they really change. By 1859

Darwin had finished his famous book The, Origin of Species. It made a great noise in the world of

science. In 1871 Darwin wrote another important book.

     Darwin continued his studies in science until he died in 1882.

1. Charles Darwin was a great _____ scientist.

A. German        

B. French

C. English          

D. American

2. As a boy, Darwin liked reading _____ books.

A. science          

B. chemistry

C. history          

D. medical

3. Darwin studied at Cambridge University _____ 1831. 

A. after          

B. since

C. before          

D. in

4. On the ship Beagle Darwin worked as a _____. 

A. teacher        

B. doctor

C. professor        

D. scientist

5. In 1871 Darwin wrote another important book _____. 

A. The Origin of Species

B. The Theory of Relativiy

C. The Theory of Evolution(《迸化论》)

D. On Practice

填空题