A (2020·全国Ⅲ·D)
We are the products of evolution，and not just evolution that occurred billions of years ago.As scientists look deeper into our genes(基因)，they are finding examples of human evolution in just the past few thousand years.People in Ethiopian highlands have adapted to living at high altitudes.Cattleraising people in East Africa and northern Europe have gained a mutation (突变) that helps them digest milk as adults.
On Thursday in an article published in Cell，a team of researchers reported a new kind of adaptation—not to air or to food，but to the ocean.A group of seadwelling people in Southeast Asia have evolved into better divers.The Bajau，as these people are known，number in the hundreds of thousands in Indonesia，Malaysia and the Philippines.They have traditionally lived on houseboats; in recent times，they've also built houses on stilts (支柱) in coastal waters.“They are simply a stranger to the land，” said Rodney C．Jubilado，a University of Hawaii researcher who studies the Bajau.
Dr.Jubilado first met the Bajau while growing up on Samal Island in the Philippines.They made a living as divers，spearfishing or harvesting shellfish.“We were so amazed that they could stay underwater much longer than us local islanders，”Dr.Jubilado said.“I could see them actually walking under the sea.”
In 2015, Melissa Ilardo, then a graduate student in genetics at the University of Copenhagen, heard about the Bajau.She wondered if centuries of diving could have led to the evolution of physical characteristics that made the task easier for them.“It seemed like the perfect chance for natural selection to act on a population，” said Dr.Ilardo.She also said there were likely a number of other genes that help the Bajau dive.
【语篇解读】 研究发现居住在东南亚的巴瑶族人为了更好地生存，进化成了更好的潜水者。
1．What does the author want to tell us by the examples in Paragraph 1?
A．Environmental adaptation of cattle raisers.
B．New knowledge of human evolution.
C．Recent findings of human origin.
D．Significance of food selection.
B [细节理解题。根据第一段中的“they are finding examples of human evolution in just the past few thousand years”可以推断，作者举例主要是为了告诉读者人类进化的新知识，故选B。]
2．Where do the Bajau build their houses?
A．In valleys. B．Near rivers.
C．On the beach. D．Off the coast.
D [细节理解题。根据第二段中的“They have traditionally lived on houseboats；in recent times，they've also built houses on stilts (支柱) in coastal waters.” 可知，巴瑶族人主要居住在沿海地区，故D项正确。]
3．Why was the young Jubilado astonished at the Bajau?
A．They could walk on stilts all day.
B．They had a superb way of fishing.
C．They could stay long underwater.
D．They lived on both land and water.
C [细节理解题。根据第三段中的“We were so amazed that they could stay underwater much longer than us local islanders”可知，年轻的Jubilado对巴瑶族人惊讶不已的地方在于他们可以在水下待很长的时间，故选C。]
4．What can be a suitable title for the text?
A．Bodies Remodeled for a Life at Sea
B．Highlanders' Survival Skills
C．Basic Methods of Genetic Research
D．The World's Best Divers
A [标题归纳题。本文是一篇研究报道，根据第二段的研究结果“a team of researchers reported a new kind of adaptation—not to air or to food，but to the ocean”可知，本文主要讲述了巴瑶族人为了更好地适应海上的生活，身体结构发生了变化，所以A项适合作本文的标题。]
