It’s not only humans that flourish in larg

题型:单项选择题

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.

The purpose of understanding the supercolonies’ forming is to ()

A. control the pests and protect beneficial species

B. understand the effects of urbanization of ants

C. help study the ant’s genetics

D. better totally dominate other species

考点:普通考研西医综合西医综合
题型:单项选择题

马克思主义哲学在确认运动绝对性的同时,也肯定相对静止的存在。物质世界是绝对运动与相对静止的统一。据此回答13-14题

小题1:“任何一个有机体,在每一瞬间是它本身又不是它本身,始终处于不间断的变化之中”。这句话是说   

①事物的变化是捉摸不定的  

②事物的运动是绝对运动和相对静止的统一   

③运动是物质的唯一特性    

④对立统一是各种运动形式的普遍联系

A.①②

B.②③

C.③④

D.②④小题2:正确表述运动、静止、条件之间关系的是

A.在一定条件下,任何事物都处于相对静止状态,即特殊的运动状态

B.对某一事物来说,运动并不一定是无条件的

C.对某一事物来说,静止并不一定是有条件的

D.在一定条件下,任何事物都处于运动状态

题型:单项选择题

预算收入划分为中央预算收入、地方预算收入、中央和地方预算共享收入。预算收入不包括()。

A.税收收入

B.依照规定应当上缴的国有资产收益

C.专项收入

D.财政转移支付

题型:单项选择题

检查变压器吸湿器中干燥剂的颜色,当大约()干燥剂的颜色显示已受潮时,应予更换或进行再生处理。

A.1/2

B.1/3

C.2/3

D.3/4

题型:单项选择题

加强腹式呼吸、缩唇呼吸训练时,做法不正确的是()

A、用鼻吸气

B、吸气时腹肌收缩

C、用口呼气

D、吸气时缩唇,缓慢呼气

E、呼气与吸气的时间比例为2:1

题型:单项选择题

目前纺织厂使用最多的原棉为海岛棉。

更多题库