题干

下列各项中,前者一定大于后者的是

A:20℃时KNO3的溶解度、80℃时KNO3的溶解度

B:30℃时NaCl不饱和溶液的质量分数、30℃时NaCl饱和溶液的质量分数

C:碳酸镁中碳元素的质量分数、碳酸氢钠中碳元素的质量分数

D:相同条件下:NaOH溶于水后溶液的温度、NH4NO3溶于水后溶液的温度

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答案(点此获取答案解析)

D

同类题3

阅读下列材料,回答问题。

材料:在俄罗斯帝国历史上,只有两个皇帝获得了“大帝”的名号:其中一个就是叶卡捷琳娜二世(1762年至1796年在位)。她上台处于俄国农奴制经济初步瓦解和阶级矛盾尖锐化的时候,叶卡捷琳娜二世在对内政策方面,大力强化专制制度、中央集权制和贵族特权,稳定国内局势,力图加强贵族官僚的国家机器,扩大贵族特权,维护和发展农奴制,颁布一系列法令,加强了贵族在各地的权力;在被征服的少数民族地区,实行强制的俄罗斯化政策。维护农奴主利益,并且她将农奴制度发展到顶点。在国家以农奴制为统治基础的时候,又明智地宣布工商业自由,取消对贸易的限制,鼓励向国外出口俄国的农副产品。称自己统治为“开明专制”(叶卡捷琳娜二世在俄国实行“开明专制”,既是受欧洲宫廷的政治风气影响,也是受法国启蒙思想家的思想推动所致)。在叶卡捷琳娜二世执政时期,俄国的工商业获得较为迅速的发展。俄国的手工工场的开工数目从1762年的984家增加到1796年的3161家。俄国的生铁产量从1760年的6万吨增加到1800年的16万吨。

    在对外政策方面,为实现其夺取世界霸权的计划,对土耳其发动了两次战争,打通了黑海口,完成了彼得大帝始终没有完成的心愿。侵占黑海北岸广大地区。同瑞典进行了战争,伙同普鲁士、奥地利3次瓜分波兰。侵占了周边领土,使俄国版图由此扩大了67万平方千米。1789年法国大革命爆发后,力图组织反法联盟,积极参与欧洲君主国镇压法国大革命,在俄国历史上开创了干涉欧洲革命的先例,使俄国成为欧洲宪兵。

同类题5

阅读理解

    On a recent visit to the Museum of Modem Art with a friend and her daughter, wandering through the museum's exhibits, I was struck by how often my friend's 13-year-old daughter asked us to take photos of her with her smart phone in front of the artwork. Then, she gazed at the photos which she would then post on Instagram, Snapchat and all the rest. She was not the only person who was doing this; it seemed everyone was busy taking photos of themselves "experiencing" the museum.

    This is by no means a criticism of my friend's daughter or anyone else. What was concerning, at least to me, was that in between being photographed and posting, my friend's daughter had no interest in the artwork, a fact which didn't seem to matter or have anything to do with wanting to post herself as someone enjoying the experience.

    When I was her age, I had no interest in going to museums either. Having no interest in art at her age (and any age) is completely normal. But what is disturbing is how much of a young person's energy these days goes into creating an image of the life they're living and the character they "are" in that life. While creating a self-image has always been a big part of growing up and figuring out our identity, social media seems to have changed the rules of the game. Social media has not just increased the pressure and possibility of creating a self-generated(自我创造的) self-image, but also distorted(歪曲) the process through which we become who we are. Young people now seem to be creating an image of who they are in place of becoming who they are, posting their life rather than living it.

    Social media has turned life and its experiences into an exercise in narcissism(自恋,自我陶醉). No matter what the experience is actually about, it becomes about you, the person who is living it. A concert is not about the music, a restaurant not about the food and a sport event not about the sport; it's all about you, the doer, and what the event says about you. As a result the more we use life create an identity, the more distant from life we feel. Instead of being part of it, we feel as if we have to keep generating new life material.

    I hope the next time you post your story, pause for a moment and experience where you are, feel what it feels like to live what you're living without using life for your benefit, or for anything at all. Just live, without the narrative(叙述). While you may feel this practice is a threat to your identity, causing you to miss a chance to prove your value, in fact, the benefit will far outweigh any loss it brings.