下列哪项对种群的基因频率没有影响 [ ] A.基因突变 B.自然选择 C.基因重

题型:选择题

问题:

下列哪项对种群的基因频率没有影响 [ ]

A.基因突变

B.自然选择

C.基因重组

D.随机交配

考点:种群基因频率的改变与生物进化
题型:选择题

概算指标在具体内容和表示方法上,有( )两种形式。

A.单项指标和分类指标

B.综合指标和单项指标

C.综合指标和分类指标

D.单项指标和分项指标

题型:选择题

选择填空。

What's wrong ______ you? [ ]

A. with

B. in

C. on

题型:选择题

细胞有丝分裂中期的染色体仅具有1个DNA分子。( )

题型:选择题

A mouse looked through a hole in the wall to see the farmer and his wife opening a package. What food might it contain? He was astonished to discover that it was a mouse trap!

  Running to the farmyard, the mouse shouted, warning, “There is a mouse trap in the house; there is a mouse trap in the house.” The chicken with her head high, said, “Shut up, Little Ugly. This is a great concern to you, but it has nothing to do with me; I cannot be bothered by it.”

The mouse turned to the pig and told him, “There is a mouse trap in the house.” “I am so very sorry, Mr. Mouse,” said the pig, “but there is nothing I can do about it but pray; you are always  in my prayers.”

  The mouse turned to the cow, who said, “A mouse trap; am I in great danger, huh?”

So the mouse had to face the farmer’s mouse trap alone.

  That very night a sound was heard through the house, like the sound of a mouse trap catching its prey. The farmer’s wife rushed to see what was caught. In the darkness, she did not see that it was a poisonous snake whose tail the trap had caught. The snake bit the farmer’s wife. The farmer rushed her to the hospital.

She returned home with a fever. It is said that drinking fresh chicken soup will help treat fever, so the farmer took his sharp knife to the farmyard for the soup’s main ingredient. His wife’s sickness continued so that friends and neighbors came to sit with her around the clock. To feed them, the farmer killed the pig.   The farmer’s wife did not get well, in fact, she died, and so many people came for her funeral. The farmer had the cow killed to provide meat for all of them to eat.

So next time someone is facing a problem, don’t say that has nothing to do with you.

小题1:We could see from the passage that the mouse was______.

A.good at cheating others

B.dishonest

C.kind and warm-hearted

D.foolish小题2:Which of the following is NOT true according to the passage?

A.The others helped the farmer kill the cow.

B.The mouse trap was very practical.

C.The pig is more friendly than the other animals .

D.The farmer’s family had no friends at all小题3:What can we learn from the story?

A.Traps can always cause chain reactions

B.Sometimes when the least of us are threatened, we all might be at risk.

C.It is better to be safe than to be sorry.

D.To keep the balance of nature is the duty of us all.

题型:选择题

用人单位因任务繁忙可以安排劳动者先从事接触职业病危害的作业,空闲后再进行上岗前职业健康检查。

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