Question

Believe it or not, the size of the human brain has become smaller over the past 20,000 years. Scientists argue over whether this means we are becoming more or less intelligent as a species.

“I’d call that a major downsizing in an evolutionary eye blink (眨眼),” John Hawks told Discover magazine.

Why is the brain becoming smaller?

There are different theories to explain it. One is that tens of thousands of years ago, before the decline began, to survive in cold and dangerous conditions, humans needed a stronger and larger body and therefore, a larger head. Also they had to chew the tough meat of rabbits, foxes and horses. As conditions improved, the brain stopped growing, according to supporters of this theory.

Another theory comes from a recent study by David Geary and Drew Bailey. They found that brain size decreased as population density(密度) increased.

“As complex societies appeared, the brain became smaller because people did not have to be as smart to stay alive.” Geary told AFP.

But smaller brain size does not necessarily mean that modern humans are less smart than their ancestors. “Modern humans simply developed different, more complex forms of intelligence,” said Brian Hare.

Hare’s studies focus on two types of great apes: chimpanzees and bonobos. Both are much like humans, but are physically quite different from one another. The bonobo has a smaller brain than the chimpanzee, and is also much less aggressive and more tolerant.

“When it comes to working out a problem,” Hare said, “chimpanzees are much less likely to accomplish it if it involves working together. Not so with bonobos.”

The smaller brain in modern humans may be evidence that we can cooperate,” Hare told the US National Public Radio.

1.Which of the following words can be used to replace the underlined word in Paragraph 2?

A. speed    B. increase

C. decline    D. change

2.We can learn from the passage that ____________.

A. the size of human brain has something to do with many factors

B. the brain size increases because of the increase of population density

C. the abilities of the bonobos and the chimpanzees are almost the same

D. modern humans can certainly do teamwork better than other species

3.According to Brian Hare, _____________.

A. bonobos are much likely to cooperate better than chimpanzees

B. chimpanzees tend to work well with others

C. modern humans are less smart their ancestors

D. small brains are certainly connected with intelligent beings

4.Which of following is probably the best title of the passage?

A. Bonobo or Chimpanzee—Which Smarter?

B. Smaller Brain--Less Intelligent?

C. Human and Animal—More Intelligent?

D. Human Brain-Why Downsizing?

Answer

1. C

2. A

3. A

4. B

【解析】

本文为说明文。在过去的2万年里，人类大脑的体积变小了。这是否意味着我们作为一个物种正变得越来越聪明呢？科学家们对此争论不休。

1.词义猜测题。根据上文the size of the human brain has become smaller over the past 20,000 years（在过去的2万年里，人类大脑的体积变小了）及构词法down（往下，向下）size（大小）可推知，downsize意为“缩小尺寸”。A. speed加速；B. increase增加；C. decline衰退；D. change改变。故C选项正确。

2.细节理解题。根据第四、五、六段的描述可知，人类大脑的大小与许多因素有关。故A选项正确。

3.推理判断题。根据倒数第二段中的Hare said, “chimpanzees are much less likely to accomplish it if it involves working together. Not so with bonobos.”（如果黑猩猩需要合作，它们完成任务的可能性就小得多。倭黑猩猩就不一样了）可推知，倭黑猩猩比黑猩猩更容易合作。故A选项正确。

4.标题判断题。文章主要介绍了在过去的2万年里，人类大脑的体积变小了。科学家们对这是否意味着我们作为一个物种正变得越来越聪明的持不同看法。B项“大脑越小——越不聪明?”适合做本文最佳标题。故B选项正确。