一份教案的核心是( )-我要搜题网

[多选题]电缆隧道应有充足的照明，并有（）的措施。
A.防火
B.防水
C.防雾
D.通风

[单选题]列消防负荷中应按Ⅱ类负荷供电的是( )。
A.单机容量为150MW的燃煤电厂的自动灭火系统
B.单机容量为200MW的燃煤电厂的自动灭火系统
C.变电站的消防水泵
D.单机容量为50MW的燃煤电厂的消防水泵

[单选题]绝缘测试各电路的绝缘值,用 500V 直流高阻绝缘表,线路应与()板断开。
A.安全电路
B.主控电路
C.电子电路
D.接线

[不定项选择题]共用题干 Ants Have Big Impact on Environment as“Ecosystem Engineers”
Research by the University of Exeter has revealed that ants have a big impact on their local environment as a result of their activity as“ecosystem engineers”and predators. The study,published in the Journal of Animal Ecology,found that ants have two distinct effects on their local environment.
Firstly,through moving of soil by nest building activity and by collecting food they af-fect the level of nutrients in the soil. This can indirectly impact the local populations of many animal groups,from decomposers to species much higher up the food chain.
Secondly,they prey on a wide range of other animals,including larger prey which can be attacked by vast numbers of ant workers.
Dirk Sanders,an author of the study from the university's Centre for Ecology and Con-servation,said:“Ants are very effective predators which thrive in huge numbers. They're al-so very territorial and very aggressive,defending their resources and territory against other predators. All of this means they have a strong influence on their surrounding area.”
“In this research,we studied for the first time how big this impact is and the subtleties of it. What we found is that despite being predators,their presence can also lead to an increase in density and diversity of other animal groups. They genuinely play a key role in the local environment,having a big influence on the grassland food web,”Sanders said.
The study,carried out in Germany,studied the impact of the presence of different combinations and densities of black garden ants and common red ants,both species which can be found across Europe,including in the UK.It found that a low density of ants in an area increased the diversity and density of other animals in the local area,particularly the density of herbivores and decomposers. At higher densities ants had no or the opposite effect,showing that predation is counteracting the positive influence.
Dr Frank van Veen,another author on the study,said:“What we find is that the impact of ants on soil nutrient levels has a positive effect on animal groups at low levels,but as the number of ants increases,their predatory impacts have the bigger effect一thereby counteracting the positive influence via ecosystem engineering.”
Ants are important components of ecosystems not only because they constitute a great part of the animal biomass but also because they act as ecosystem engineers. Ant biodiversity is incredibly high and these organisms are highly responsive to human impact,which obviously reduces its richness. However,it is not clear how such disturbance damages the maintenance of ant services to the ecosystem. Ants are important in below ground processes through the alteration of the physical and chemical environment and through their effects on plants,microorganisms,and other soil organisms. What still remains unclear about ants,according to the last paragraph?
A.What roles do ants play in the ecosystem in which they live?
B.How do ants affect the animal diversity in a given ecosystem?
C.How do human activities affect ants'influence on a given ecosystem?
D.How do ants alter the physical and chemical environment?

[单项选择]一份教案的核心是( )A. 提出教学目的B. 选择教学方法C. 涉及教学进程D. 规划板书内容

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[单项选择]一份教案的核心是( )
A. 提出教学目的
B. 选择教学方法
C. 涉及教学进程
D. 规划板书内容