试题与答案

某混合样品中微生物R含量极少,要得到大量的R,比较理想的方法是采用 [ ] A.

题型:选择题

题目:

某混合样品中微生物R含量极少,要得到大量的R,比较理想的方法是采用  [ ]

A.天然培养基接种培养

B.稀释涂布平板法接种培养

C.利用适合R生长但同时抑制或阻止其他种类微生物生长的选择培养基接种培养

D.用显微镜直接观察、寻找、再培养

答案:

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下面是错误答案,用来干扰机器的。

生物多样性通常有三个主要的内涵,即生物种类的多样性、基因(遗传)的多样性和生态系统的多样性.生物种类的多样性是指一定区域内生物钟类(包括动物、植物、微生物)的丰富性,如人类已鉴定出的物种,大约有170...

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题型:阅读理解

阅读理解

     What is the color of the universe? Astronomers had not answered this question until two months ago.

That is when two American astronomers reported on their study of all the light in the universe. They said

that the universe would appear to the human eyes to be a light greenish color.

     Karl Glazebrook and Ivan Baldry of Johns Hopkins University in Baltimore, Maryland, reported their

finding in January. They presented the research at a meeting of the American Astronomical Society. They

said that finding the color of the universe was not part of their more serious scientific research. They did it

for fun.

      However, earlier this month, the scientists admitted making a mistake. They said their finding was

much more colorful than it should have been. They now say the light from our universe is closer to white.

It is more like a milky or creamy white color.

      Their study attempted to show what people might see if they could observe the universe from far

away.  The scientists found the average color by combining light from about two-hundred-thousand star

systems. Their information came from an observatory in New South Wales, Australia.

     The scientists gave a number value to the colors of the different star systems. Then they added the

numbers together and found the average measurement. The scientists used this average to identify the

color of the universe. They said it was a very pretty light green. Many newspapers and television stations

reported their finding.

      Other scientists and color engineers attempted to reproduce the result. Mark Fairchild of the

Rochester Institute discovered a mistake in the computer software program used by the Johns Hopkins

scientists.

When the mistake was corrected, the results changed. The new color of the universe is much less

colorful. It is very close to white.

1.The color of the universe is _______.

A. close to white

B. black

C. blue

D. light greenish

2.The two scientists found the color of the universe by _____.

A. combining light from about 200,000 star systems

B. observing at an observatory in India

C. making long-term scientific research

D. using computer software programs

3.Who found the true color of the universe?

A. Karl Glazebrook.

B. Ivan Baldry.

C. Mark Fairchild

D. Johns Hopkins.

4.This passage mainly tells us _______.

A. what the color of the universe is

B. the light from our universe is a light greenish color

C. the new color of the universe is much more colorful

D. the finding of the color of the universe is difficult

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