"Natural selection" means
A、selected by nature
B、selected for nature
C、selected by man for nature
D、selected in nature
A、selected by nature
B、selected for nature
C、selected by man for nature
D、selected in nature
The main idea of the passage would be__________.
A.why natural selection leads to population increase over generation
B.how natural selection maintains and changes the makeup of a population
C.why natural selection created the large brain size in human beings
D.how natural selection promotes individuals who care for their offspring
Which of the following is NOT true about natural selection?
A.Natural selection favors adaptations that help a species to Survive.
B.Natural selection works against extreme changes in a species.
C.Natural selection allows helpful, new traits to spread through a population.
D.Natural selection occurs in periods of severe environmental disturbances.
The main point of this passage is ______.
A.evolution of speech
B.darwin's law of natural selection
C.progress of human brains
D.evolution of human intelligence
The topic of this passage would be______.
A.why natural selection leads to population increase over generations
B.how natural selection maintains and changes the makeup of a population
C.why natural selection created the large brain size in human beings
D.how natural selection promotes individuals who care for their offspring
According the theory of kin selection, humans tend to act altruistically
A.for the sake of desired reproduction.
B.out of self-interest.
C.on the request of natural selection.
D.because of kind nature.
According to paragraph 1, what is the end result of natural selection?
A.Special individuals.
B.New species.
C.Random traits.
D.Adapted characteristics.
A、mutation
B、natural selection
C、equilibrium
D、evolution
E、sampling error
Natural selection acts in the form. of variation with a species.
A.Y
B.N
C.NG
听力原文:W: Professor Marnes, I wonder if you can fill me in on your lecture last Friday. I had to attend a scholarship award ceremony.
M: Oh well, congratulations. I hope you were rewarded handsomely!
W: Well, every bit helps. So, about your lecture, I understand you were talking about extinctions.
M: Yes. Well, the crux of my talk was just that we tend to think of extinction as a dramatic event, but most species die out over quite a period of time.
W: Why do they die off? I thought they were continuously improving themselves. Natural selection, I think you once mentioned.
M: Ah, but you see while there is natural Competition between the species, what determines which species survive is largely by chance.
W: I don't get it. Why do species bother competing?
M: Well, there are short-term advantages. But many species also are helped by others. For example, the common housefly and cockroaches might have died off years ago if not for humans.
W: But you're not saying that humans are so successful merely because of chance?
M: To a certain extent, humans were initially lucky enough to have the right weather conditions and a lack of predators, but now, of course, we survive by ingenuity!
W: go we may never become extinct.
M: No, because we may be in a crash course to extinction by our continuous exploitation of the environment. We are a relatively young species and our time is hot yet overdue.
W: But there are 6 billion of us!
M: Yes and there're many more houseflies too! Each with the capacity to spread one disease from one person to another in a fast period of time.
(20)
A.She is writing a competitive paper for a scholarship.
B.She is doing a paper.
C.She missed the lecture.
D.She is planning to attend the scholarship award ceremony.
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