Question

    Calling someone a “birdbrain” is considered rude. It implies that someone has a small brain and thus is not smart. A new study found that the expression doesn’t do birds justice either. Birds’ brains are much bigger than we thought-at least compared to their small bodies.

An international team of 37 scientists measured the brain volume of hundreds of dinosaurs and extinct birds by scanning fossils of their skulls. The readings were compared to a large database containing the brain sizes of modern birds. These measurements were then analyzed, taking into consideration each bird’s body size-resulting in something called “relative brain size”. The results showed that a dramatic change of birds’ body size happened right after the mass extinction of dinosaurs 66 million years ago.

According to the study, published on April 23 in the journal Current Biology, birds and non-avian (非鸟类的) dinosaurs had similar brain sizes before the extinction. After the extinction of the dinosaurs, however, birds had to find a way to survive, so they shrank their bodies-since smaller animals need less food-but they kept their big brains.

“The changed landscape may have caused the rapid evolution of new brain-body scaling patterns (缩放比例) by favoring both larger brains and smaller bodies,” US paleontologist (古生物学家) Daniel Ksepka, who is the lead author of the study, told CNN.

This “evolutionary brain leap”-as scientists call it-also happened very rapidly. Without dinosaurs, birds quickly repopulated. They came in all types and sizes, which contributed to the diverse species of birds we see today.

But among all the bird species, certain ones “show above average rates of brain and body size evolution”, study co-author Adam Smith at Clemson University, US, said in a statement-with crows and parrots being the most evident. In fact, previous studies have already discovered that these birds have an amazing cognitive ability. They are able to use tools, imitate human speech and even remember human faces.

So, in the words of Smith, “calling someone ‘bird-brained’ is actually quite a compliment!”

1.How did scientists learn the brain sizes of dinosaurs and extinct birds?

A.By referring to a database.

B.By analyzing their body size.

C.By studying their fossil skulls.

D.By examining the brain size of modem birds.

2.What were birds’ brains like after the extinction of the dinosaurs?

A.They were the same size as non-avian dinosaurs.

B.They shrank to adapt to the environment.

C.They kept growing to avoid extinction.

D.They remained as big as they were before.

3.According to Adam Smith, what do we know about birds?

A.Their brain evolution happened very rapidly.

B.Some species evolved to be smarter than others.

C.Crows and parrots have the largest bird brains.

D.Birds have amazing abilities to copy human speech.

4.What is the purpose of this text?

A.To explain the origin of the word “birdbrain”.

B.To describe how a bird evolved through history.

C.To present a new study on birds’ brain size.

D.To reveal reasons for the rapid growth of bird populations.

Answer

1.C

2.D

3.B

4.C

【解析】

本文为一篇说明文。文章介绍了称呼某人为“鸟人”，意味着一个人的大脑很小。最新科学研究表明，鸟类的大脑十分发达。

1.

细节理解题。根据第二段An international team of 37 scientists measured the brain volume of hundreds of dinosaurs and extinct birds by scanning fossils of their skulls. 一个由37名科学家组成的国际研究小组通过扫描恐龙和灭绝鸟类的头骨化石，测量了它们的大脑体积。可知，科学家是通过研究恐龙和灭绝鸟类的头骨化石，得知它们的大脑的大小的。故选C项。

2.

细节理解题。根据第三段After the extinction of the dinosaurs, however, birds had to find a way to survive, so they shrank their bodies-since smaller animals need less food-but they kept their big brains. 然而，恐龙灭绝后，鸟类不得不寻找生存之道，因此它们缩小了身体，因为较小的动物需要更少的食物，但它们保留着它们大脑的大小。可知，恐龙灭绝后，鸟类的大脑仍然像以前一样大。故选D项。

3.

细节理解题。根据倒数第二段But among all the bird species, certain ones “show above average rates of brain and body size evolution”, study co-author Adam Smith at Clemson University, US, said in a statement-with crows and parrots being the most evident. 但在所有鸟类中，某些鸟类“大脑和体型的进化速度高于平均水平”，这项研究的合著者、美国克莱姆森大学的亚当·史密斯在一份声明中说，乌鸦和鹦鹉是最明显的。因此，根据亚当·斯密的说法，有些鸟类能进化的比其他鸟类更聪明。故选B项。

4.

推理判断题。根据第一段A new study found that the expression doesn’t do birds justice either. Birds’ brains are much bigger than we thought-at least compared to their small bodies.（一项新的研究发现，这个表达对鸟类也不公平。鸟类的大脑比我们想象的要大得多——至少和它们小的身体相比是这样。）结合全文，可知文章介绍了对鸟类大脑的研究，发现鸟类的大脑十分发达，有些鸟类甚至有惊人的认知能力。由此推知，写这篇文章的目的是展示一项关于鸟类大脑大小的新研究。故选C项。