It’s not only humans that flourish in larg

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问题:

It’s not only humans that flourish in large settlements. Some ants find urban life so accommodating that their populations explode and they form supercolonies in cities.

"One of the most common house ant species might have been built for living in some of the smallest spaces in a forest, but the ants have found ways to take advantage of the comforts of city living," Purdue University said in a statement. Grzegorz Buczkowski, a Purdue University research assistant professor of entomology, discovered odorous house ants live in supercolonies, creating complex networks entomologists have never seen with the species before now. He found that odorous house ant colonies become larger and more complex as they move from forest to city and act somewhat like an invasive species, the university said. "The ants live about 50 to a colony with one queen in forest settings but explode into supercolonies with more than 6 million workers and 50 000 queens in urban areas," the university explained.

"This is a native species that’s doing this," said Buczkowski, whose results are published in the early online version of the journal Biological Invasions. "Native ants are not supposed to become invasive. We don’t know of any other native ants that are outcompeting other species of native ants like these," Buczkowski said. Odorous house ants live in hollow acorn shells in the forest. They’re called odorous because they have a coconut (椰子)-or rum-like smell when crushed. They’re considered one of the most common house ants, Purdue said. In semi-natural areas that are a cross of forest and urban areas, such as a park, Buczkowski said he observed colonies of about 500 workers with a single queen. "It’s possible that as the ants get closer to urban areas they have easier access to food, shelter and other resources," he said.

"In the forest, they have to compete for food and nesting sites," Buczkowski said. "In the cities, they don’t have that competition. People give them a place to nest, food to eat. " Buczkowski observed the ants in three different settings on and around the Purdue campus. He said it might be expected that if the odorous house ants were able to multiply into complex colonies, other ants would do the same. But Buczkowski found no evidence that other ants had adapted to new environments and evolved into larger groups as the odorous house ants have, Purdie said. "It’s possible that odorous house ants are better adapted to city environments than other ant species or that they had somehow outcompeted or dominated other species," he said. "This raises a lot of questions we’d like to answer. " Buczkowski said understanding why the supercolonies form could lead to better control of the pests in homes, as well as ensuring that they don’t outcompete beneficial species.

Future studies on odorous house ants will include studying the ant’s genetics and trying to understand the effects of urbanization of odorous house ants, Purdue said.

According to the third paragraph, native ants are ()

A. liable to become aggressive

B. not prone to be offensive

C. able to outcompete other ants

D. easily attacked by other ants

考点:普通考研西医综合西医综合
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一个数的立方根等于它本身,这个数是(  )
A.0B.1C.0或1D.0或±1
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下列各句中,加点的成语使用恰当的一句是()

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B.中国寺庙建筑宏大精美,因势构筑巧思妙想,真可谓鬼斧神工,令人叹服。

C.义门是陈村最古老的建筑,与义门形影相吊的是它的左侧立着一株无枝无叶的老树。

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肺动脉瓣狭窄的心脏杂音特点是()

A.心脏听诊杂音向左腋下及左肩胛下角处传导

B.心脏听诊杂音向胸骨下端或心尖部传导

C.心脏听诊杂音向上传至右侧胸骨上窝及颈部

D.心脏听诊杂音局限于胸骨左缘第2肋间

E.心脏听诊杂音局限于胸骨左缘第3、4肋间

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220kV负荷线,重合闸一般采用()

A.单重方式

B.三重方式

C.综重方式

D.自适应重合方式

题型:单项选择题

举例说明注意的几种类型及其特征。

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