题干

有一个长方体容器,装的水恰好占其容积的一半;表示水平的桌面,容器一边紧贴桌面,沿将其翻转使之倾斜,最后水面(阴影部分)与其各侧棱的交点分别是(如图),设翻转后容器中的水形成的几何体是,翻转过程中水和容器接触面积为,则下列说法正确的是(  )

A:是棱柱,逐渐增大

B:是棱柱,始终不变

C:是棱台,逐渐增大

D:是棱台,

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答案(点此获取答案解析)

B

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阅读理解

    Animal training refers to teaching animals specific responses to specific conditions or stimuli (刺激). Training may be for the purpose of companionship, detection, protection, entertainment or all of the above.

    An animal trainer may use various forms of reinforcement (强化) or punishment to condition an animal's responses. There are many ways to train animals and as a general rule no legal requirements or certifications (证书) are required.

Chickens

    Training chickens has become a way for trainers of other animals (primarily dogs) to perfect their training technique.  Bob Bailey, former director of Animal Behavior Enterprises and the IQ Zoo, teaches in chicken training courses where trainers teach chickens to tell different shapes, to navigate an obstacle course and to chain behaviors together.

Fish

    Fish can also be trained. For example, a goldfish may swim toward its owner and follow him as he walks through the room, but will not follow anyone else. The fish may swim up and down, signaling the owner to turn on its aquarium (鱼缸) light when it is off, and it will skim the surface until its owner feeds it. Pet goldfish have also been taught to perform more complicated tasks, such as doing the limbo (a kind of dance) and pushing a miniature soccer ball into a net.

Pigs

    Among all animals, they are the third cleverest — monkeys, dolphins and pigs. Scientists think the training of pigs is easier than the training of dogs and cats. Pigs have a very good sense of smell. They can find things nearby or faraway. They can also help the police to find out drugs at an airport or at a train station.