题干

为了探究胰岛素的作用,某同学以小鼠的活动状况为观察内容,设计了如下实验。

第一步,将若干只正常的小鼠,平均分为A、B两组。观察并记录小鼠的活动状况。

第二步,给A组小鼠注射适量的胰岛素溶液,给B组小鼠注射等量的生理盐水。一段时间后,A组小鼠会出现四肢无力、活动减少等低血糖症状,B组小鼠活动正常。

第三步,在A组小鼠出现低血糖症状后,分别给A、B两组小鼠注射等量葡萄糖溶液。一段时间后,A组小鼠恢复正常活动,B组小鼠没有明显变化。

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同类题2

阅读理解

    Personal planes which can take off noiselessly from the back garden will be possible within two years.

    Lilium Aviation is inventing an electric two-seater airplane which  takes just 20 hours to learn to fly and can travel at speeds of  250mph.More importantly, the small plane, which weighs just 25kg, can take off vertically which means it does not need to fly from an airport, but could be parked outside a house or in a garden. The company says the design will “open the door to a new class of simpler, quieter and environmentally friendly planes” and will be possible from 2018.

    “Our goal is to develop an airplane for use in everyday life,” said Daniel, CEO and one of the company's four founders. "We are going for a plane that can take off and land vertically and does not need the difficult and expensive infrastructure of an airport.

    Although helicopters offer a choice, they are very noisy and difficult to fly and require expensive licenses. They also have no backup if the rotor fails, making them costly to build and keep. While firstly limited to airfields, the Lilium airplane will eventually take off vertically from almost anywhere – even from back gardens – it needs only an open flat area of 50 ft. by 50ft (15 m x 15m).

    The plane is classed as a Light Sport Aircraft for two users, with the pilot's license requiring 20 hours' minimum training – almost like taking a driving license. It is intended for fun flying during daylight, in good weather conditions and in least crowded airspace up to 3 km altitude. The airplane would have to follow the same flight laws as helicopters.

同类题4

阅读下文,完成问题。

读书是一种德性

丁国强

    读书是一种发自内心的选择。当一个人强迫着自己作出某种读书姿态的时候,他其实是在折磨自己了。读书是一种心灵的义务。一个人,如果没有把一段青春时光托付给高贵的思想和真诚的文字,那么,他就是自己的敌人,因为他放弃了对自我心灵的塑造,错过了在读书时光中体会“物我两忘” 的机缘。这一机缘,错过了,就永远无法弥补。当你回过头来,重新拾起书本的时候,你会发现自己是何等的陌生!古人三日不读书,便觉得面目可憎,更何况是错过了一段读书的岁月呢?

    读书作为一种生活习惯,绝不是随便什么人都可以享有的。它是无条件的,完全是自我选择的结果。曾国藩有言:“苟能发愤读书,则家塾可读书,旷野之地、热闹之地亦可读书;负薪牧豕,均无不可读书。苟不能发愤自立,则家塾亦不能读书,即清净之乡、神仙之境皆不能读书。何必择地?何必择时?”这段话可以从更广阔的意义上去理解,说白了,之所以不读书,首先是因为你不想读书,而并非客观条件不具备。

    我读故我思。表面上看来,思想者与无知者的差别或许就在一本书。一本书所产生的精神距离是无法测量的。思想者的沉默,本身就昭示着一种精神力量,而无知者越是煤党不休,越发暴露其内心的苍白。但是读书并不意味着手不释卷,阅读是一种内在的精神仪式,它的存在不依赖于外在的表演。一个曾经有过一段疯狂的阅读史的人,一个对过去的读书生活心怀依恋的人,即便不能拥有一个书房,一面书橱,一盏书灯,一个畅游书海的安静夜晚,我们依然相信他那份纯洁的读书情感。

    读书是一种德性。在理性的引导下,读书人在灿烂星空与神圣道德律之间,获得了灵性和自由,以及诗意的生存。