Question

    How and why, roughly 2 million years ago, early human ancestors evolved large brains and began fashioning relatively advanced stone tools, is one of the great mysteries of evolution. Some researchers argue these changes were brought about by the invention of cooking. They point out that our bite weakened around the same time as our larger brains evolved, and that it takes less energy to absorb nutrients from cooked food. As a result, once they had mastered the art, early chefs could invest less in their digestive systems and thus invest the resulting energy savings in building larger brains capable of complex thought. There is, however, a problem with the cooking theory. Most archaeologists (考古学家）believe the evidence of controlled fire stretches back no more than 790,000 years.

Roger Summons of the Massachusetts Institute of Technology has a solution. Together with his team, he analyzed 1.7 million-year-old sand-stones that formed in an ancient river at Olduvai Gorge in Tanzania. The region is famous for the large number of human fossils (化石) that have been discovered there, alongside an impressive assembly of stone tools. The sand-stones themselves have previously yielded some of the world’s earliest complex hand axes — large tear-drop-shaped stone tools that are associated with Homo erectus (直立人) . Creating an axe by repeatedly knocking thin pieces off a raw stone in order to create two sharp cutting edges requires a significant amount of planning. Their appearance is therefore thought to mark an important moment in intellectual evolution. Trapped inside the Olduvai sand-stones, the researchers found distinctive but unusual biological molecules（分子）that are often interpreted as biomarkers for heat-tolerant bacteria. Some of these live in water between 85°C and 95°C. The molecules’ presence suggests that an ancient river within the Gorge was once fed by one or more hot springs.

Dr. Summons and his colleagues say the hot springs would have provided a convenient “pre-fire” means of cooking food. In New Zealand，the Maori have traditionally cooked food in hot springs, either by lowering it into the boiling water or by digging a hole in the hot earth. Similar methods exist in Japan and Iceland, so it is plausible, if difficult to prove, that early humans might have used hot springs to cook meat and roots. Richard Wrangham, who devised the cooking theory, is fascinated by the idea. Nonetheless, fire would have offered a distinct advantage to humans, once they had mastered the art of controlling it since, unlike a hot spring, it is a transportable resource.

1.All of the following statements can support the cooking theory EXCEPT__________.

A.cooking enabled early humans to invest less in digestive system

B.cooking enabled early humans to devote more energy to building big brains

C.our brain became larger around the same time our digestive system weakened

D.the controlled fire wasn’t mastered until about 790,000 years ago

2.The presence of biological molecules was important because_________.

A.they suggested a possible means of cooking without fire

B.they cast light on how early Homo erectus lived

C.they provided a convenient way of studying stone tools

D.they made studies of pre-historic cultures possible

3.The underlined word “plausible” probably means _________.

A.noticeable B.applicable

C.reasonable D.affordable

4.What may be the conclusion of the study by Dr. Summons and his colleague?

A.Early humans were capable of making complex stone tools.

B.Hot springs help explain how human brains got so big.

C.Homo erectus were adaptable to tough and complex territories.

D.Human brains are highly advanced as shown by their size.

Answer

1.D

2.A

3.C

4.B

【解析】

本文是一篇说明文，介绍了烹饪有助于早期类祖先进化出了巨大的大脑。

1.细节理解题。根据第一段中的“They point out that our bite weakened around the same time as our larger brains evolved, and that it takes less energy to absorb nutrients from cooked food. As a result, once they had mastered the art, early chefs could invest less in their digestive systems and thus invest the resulting energy savings in building larger brains capable of complex thought. There is, however, a problem with the cooking theory. Most archaeologists (考古学家）believe the evidence of controlled fire stretches back no more than 790,000 years”可知，他们（研究人员）指出，我们的咬合能力在大脑进化的同时减弱，从熟食中吸收营养所需的能量更少。因此，一旦掌握了这门艺术，早期的厨师就可以减少对消化系统的投资，从而将由此节省的能源投资于培养能够进行复杂思考的更大大脑，然而，烹饪理论有一个问题，大多数考古学家认为，控制火的证据可以追溯到不超过79万年前，由此可知，A、B、C三项可以支持烹饪理论，而D则不能，故D项正确。

2.细节理解题。根据第二段中的“the researchers found distinctive but unusual biological molecules（分子）that are often interpreted as biomarkers for heat-tolerant bacteria. Some of these live in water between 85°C and 95°C. The molecules’ presence suggests that an ancient river within the Gorge was once fed by one or more hot springs.”可知，研究人员发现了独特的生物分子，通常被解释为耐热细菌的生物标志物，其中一些生活在85°C到95°C之间的水中，这些分子的存在表明，峡谷内的一条古老河流曾经由一个或多个温泉提供水源，再结合第三段中的“Dr. Summons and his colleagues say the hot springs would have provided a convenient “pre-fire” means of cooking food.”可知，萨曼斯博士和他的同事们说，温泉可以提供一种方便的在使用火前烹饪食物的方法，由此可知，生物分子的存在很重要是因为它们显示了不用火做饭的可能方法，故A项正确。

3.词义猜测题。根据画线词前的“In New Zealand，the Maori have traditionally cooked food in hot springs, either by lowering it into the boiling water or by digging a hole in the hot earth. Similar methods exist in Japan and Iceland”可知，在新西兰，毛利人有在温泉里煮食物的传统，他们要么把食物放入滚烫的水中，要么在滚烫的泥土上挖一个洞，类似的方法在日本和冰岛也存在，所以早期人类可能用温泉煮肉和树根是合理的，由此可知画线词词义为“合理的”，故C项正确。

4.推理判断题。根据第一段中的“How and why, roughly 2 million years ago, early human ancestors evolved large brains and began fashioning relatively advanced stone tools, is one of the great mysteries of evolution. Some researchers argue these changes were brought about by the invention of cooking.”可知，大约200万年前，人早期类祖先是如何和为何进化出了巨大的大脑，并开始形成相对先进的石器，这是进化的一大谜团，一些研究人员认为，这些变化是烹饪的发明带来的，再根据第三段中的“Dr. Summons and his colleagues say the hot springs would have provided a convenient “pre-fire” means of cooking food.”可知，萨曼斯博士和他的同事们说，温泉可以提供一种方便的在使用火之前烹饪食物的方法，也就是说温泉是早期人类烹饪方法之一，由此可知，萨曼斯博士和他的同事们会得出这样的结论，即：温泉有助于解释人类的大脑是如何变得如此之大的，故B项正确。