问题 选择题

为了能够回到故乡的河流中产卵繁衍后代,大麻哈鱼必须经历千难万险的长途跋涉。在长途跋涉过程中,之所以能够躲过激流险滩,主要原因是(  )

A.身体两侧具有侧线

B.用鳍游泳

C.用鳃呼吸

D.体表覆盖鳞片

答案

答案:A

题目分析:鱼的视力很弱,无眼睑,它的晶状体不能调节,但它的另外一种感觉器官--侧线很发达,侧线是鱼的主要感觉器官。鱼体两侧的由许多小孔排列而成的线条,这些小孔称侧线管孔,小孔分布在一些鳞片上,小孔下面互相连通,形成长管,叫做侧线管。管中充满黏液,外界水流的刺激经过鳞片上的侧线管孔传达到侧线管中的感觉细胞,可以产生兴奋,兴奋经神经传递给脑,就能产生水流感觉。鱼类通过侧线可以感知水压大小、水流方向、水流速度、水中物体的位置和其他各种变化。故A正确。

阅读理解

阅读理解。

     Robert Owen was born in Wales in 1771. At the age of ten he went to work. His employer had a large

Private library, so Owen was able to educate himself. He read a lot in his spare time and at nineteen he was

given the job of superintendent (监工) at a Manchester cotton mill. He was so successful there that he

persuaded his employer to buy the New Lanark mill in Scotland.

     When he arrived at New Lanark it was a dirty little town with a population of 2,000 people. Nobody paid

any attention to the workers' houses or their children's education. The conditions in the factories were very

bad. There was a lot of crime and the men spent most of their wages on alcoholic drinks.

     Owen improved the houses. He encouraged people to be clean and save money. He opened a shop and

sold the workers cheap, well-made goods to help them. He limited the sale of alcoholic drinks. Above all, he

fixed his mind on the children's education. In 1816 he opened the first free primary school in Britain.

     People came from all over the country to visit Owen's factory. They saw that the workers were healthier

and more efficient than in other towns. Their children were better fed and better educated. Owen tried the

same experiment in the United States. He bought some land there in 1825, but the community was too far

away. He could not keep it under control and lost most of his money.

     Owen never stopped fighting for his idea. Above all he believed that people are not born good or bad.

     He was a practical man and his ideas were practical. "If you give people good working conditions," he

thought, "they will work well and, the most important thing of all, if you give them the chance to learn, they

will be better people."

1. For Owen, his greatest achievement in New Lanark was _____.[ ]

A. improving worker's houses

B. helping people to save money

C. preventing men from getting drunk

D. providing the children with a good education

2. From the passage we may infer that Owen was born _____. [ ]

A. into a rich family

B. into a noble family

C. into a poor family

D. into a middle class family

3. Owen's experiment in the United States failed because _____. [ ]

A. he lost all his money

B. he did not buy enough land

C. people who visited it were not impressed

D. it was too far away for him to organize it properly

4. We may infer form the passage that no children in Britain could enjoy free education until _____. [ ]

A. 1771

B. 1816

C. 1825

D. 1860

单项选择题