题干

 一个物体放在水平桌面上,下列一对力中是平衡力的是(  )

A:物体受到的重力和物体对水平桌面的压力

B:物体受到的重力和水平桌面对物体的支持力

C:物体受到的支持力和物体对水平桌面的压力

D:桌子受到的重力和物体对水平桌面的压力

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答案(点此获取答案解析)

B

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阅读理解

    Many people don't consider their breakfast without a glass of milk. Right now, cows, buffalos, goats and sheep provide most of the world's milk. But soon, people could get milk from roaches(蟑螂).

    That isn't as crazy as it might sound. New research shows this “milk” is super-nutritious. What's more, some scientists have already begun referring to a lot of insects as source of milk.

    In 2004, Subramanian Ramaswamy started studying milk crystals found inside the roach. At the time, he was teaching biochemistry at the University of Iowa City.

    To learn more about the milk crystal from roaches, the scientists used X-rays to look at the atoms in it. The data basically revealed the chemical recipe of the roach crystal. They showed that roach milk is a “complete food”. It contains sugar with a fatty acid stuck to it. Fatty acids are the building blocks of fats. The protein in the milk is also full of essential amino(氨基的) acids, which are the building blocks of proteins. Since our bodies can't produce the “essential” ones, we need to get them from our food. And so do baby roaches.

    Barbara Stay, a biologist at Iowa University, also worked on the new study. She says the new data show that the roach milk is “three times more nutritious than cow's milk and four times more nutritious than buffalo's milk”.

    Ramaswamy would like to see roach milk turned into a protein supplement to feed hungry people. But not everyone is confident that it can be done.

    Marcel Dicke studies insects as a potential source of human food at Wageningen University in the Netherlands. Dicke says this is a “sound study”. However, in his opinion, “Extracting(提取) milk from roaches can only likely be done in a destructive way with only small quantities”. That means you'd have to raise and kill many bugs to get even tiny quantities of the milk.

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                                                                           读书不妨多一些“慢阅读”
                                                                                      耿银平 
      ①4月23日是 “世界读书日”,为了让读书活动成为更多人的精神爱好,品味到读书的快乐和雅趣,不妨多一些“慢阅读”的意识。
      ②所谓“慢阅读”,是指虽然当下进入了“加急时代”、“超音速发展时代”,读书,却仍需要优哉游哉的慢节奏、慢速度以及慢情调。因为只有在“慢”中,与生俱来的机智情趣,才能和书香琴韵达成自然衔接,读书应该完成的精神活动,“体验”、“思考”、“质疑”、“沉淀”才能完成得从容不迫、饱满自在。最重要的是,只有“慢”,兼收并蓄才能得到充分实现,让厚重书香成为人格发展的重要构成。人因为爱书,所以智慧不断提高,书因为有了人的青睐赏爱,而陡增诸多妙趣。
      ③其实,从思维发展规律方面认识慢阅读,也是很有科学性的。思维是活生生的精神活动,是一种灵感的产物,所以,就需要给予它足够的时间积蓄、思考余地和宽松环境。
      ④遗憾的是,电子阅读提高了阅读效率,也陷入了不少误区。其一,读书速成化,不论看什么书籍,都喜欢速战速决,蜻蜓点水,错过了“品味”的好时机。其二,就是俗浅化,满足于走马观花,比如很多人热衷于读图和漫画,宁愿让幽默化的图画牵着 “思维鼻子”,也不愿主动探究、提出质疑和深度思考。其三,就是功利化。对有用的图书非常着迷,而对于那些所谓的名著和闲书置之不理,正如读书推广大使白岩松所言,“走到新华书店,全是一些有用的书,考试类的健康类的工具书啊。这个社会都在倡导有用,什么叫有用呢?跟钱、权、名利有关,就有用!”
      ⑤上述读书看似有成就,轰轰烈烈,其实不然。因为思考不够深入,印象不够深刻,往往会成为“速朽”,陷入“快速、快感、快扔”的读书模式中。
      ⑥这种阅读倾向更容易让人们的精神气质变得非常浮躁和极端功利化,而将最应该坚守的情趣、品格和高尚人格忘掉一边;干什么事情都喜欢急于求成,不愿意等待和遵循循序渐进的规律。很多中学生“无心读名著”,不正是这种浮躁心态的表现吗?
      ⑦因此,更多人读书的时候,应该慢阅读。注重心灵和图书的微妙互动,多培养恬淡闲适、从容独立、质疑探索、自由发展的读书性格,从高品质文字中寻觅乐趣和意义,真正闻得到书香,为自己带来更多的精神愉悦、发展进步!