题干

甲、乙两种物质的溶解度曲线如图所示,下列说法正确的是(   )

A:t2 时,甲物质的饱和溶液溶质质量分数为50%

B:乙物质的溶解度小于甲物质的溶解度

C:t2 时,乙的饱和溶液降温至 t1 ,乙溶液变为不饱和溶液

D:当甲中含有少量乙时,可以用降温结晶提纯甲

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答案(点此获取答案解析)

D

同类题2

阅读下面议论文,完成小题。 

给最爱的他们安全感

沈奇岚

       每个孩子都被父母指责过不懂事,那句“都是为了你好”听过千遍万遍,“知道,知道,我都知道”也答了千遍万遍。为什么这样的事情一直在发生?

       我们的父母有个有趣的标准,听话的就是好孩子,不听话的就是坏孩子。换言之,就是停留在父母框架里的就是父母喜欢的孩子,任何突破框架的企图都是叛逆、不听话、不懂事甚至不孝顺。

       你想自己做决定,想过自己的人生。但是,在父母的框架里,你常常碰壁。他们希望你留在那个框架里面,因为他们怕你出去了会不安全。

       当我们还是小孩子的时候,父母的框架都是保护性的,“不要和陌生人说话”、“饭前要洗手”、“听老师的话”等等。那是他们的人生经验,他们用自己对世界的认识来为我们筑起保护墙。但是任何框架都可能陷入一种惯性。他们习惯了这种保护你的方式,却还没有习惯你已经长大,世界已经发生巨大的变化。你想要空间,不得不和这个框架发生冲突。你没办法责怪他们,他们的框架都是出于爱。你在他们的框架之内,他们才觉得你是安全的,他们才有安全感。

       很多年以后,你会发现,父母对我们人生的横加干涉,无非是怕我们做了糟糕的选择──他们心里没有安全感,对框架之外的世界没有信心。

       如果你希望父母尊重你的选择,你必须要给他们安全感──你能对自己的选择负责。可以从小事做起,甚至从妥协做起。独立从来不是别人给的,而是自己用脚踏实地的行为挣来的。让父母有安全感有两条路,一条是最方便的听话之路,父母要求你做什么就做什么。这条路在你长大之后会越来越难走,你会分不清楚“他们想要什么”和“你想要什么”。

       一条就是有些难度的独立之路,你要比他们更强大。这句话的意思不是你要通过压倒他们来达到强大,而是你要通过理解他们和保护他们变得更强大,强大到他们能够意识到你能照顾好自己了,甚至能照顾他们了。不要等他们老了,你才觉得该照顾他们了。说到这里,你会不会笑──给父母安全感?

       真的,试试从这个角度去理解你们的关系,就会明白许多的冲突并不是他们不尊重你,而是他们没有安全感,他们不知道你已经长大。他们的横加干涉可能是一种过度的担心,是一种婉转但是失败的爱的表达。

       坦白地说,期待父母因为你而有所改变,恐怕是种奢望。所以你要更努力,试着去理解自己的父母,理解他们的怕与爱,理解他们的局限、他们的爱好、他们的愿望。

       其实当父母是世间最辛苦的工作,为了保护他们的孩子,哪怕自己碰得鼻青脸肿也要努力强大。他们为你提供了那么长久的爱和安全感,现在,轮到你了。长大吧!

(选自2010年第19期《读者》)

同类题5

完形填空

The spirits of giving

    Two weeks before Christmas, two girls were walking down the street, laughing on some ice that remained from a recent snow. Merrily they shared what they hoped to 1from Christmas.

    They stopped to talk to an old man named Harry, who was on his knees2weeds around a large oak tree. He wore a pair of 3garden gloves. His fingers were sticking out of the ends, blue from the4.

    Harry told them he was getting the yard in 5as a Christmas gift for his mother, who had died several years before. He said with his eyes 6with tears,"My mother was all I had. She loved her7and her trees, so I do this for her at Christmas."

    His words8the girls and soon they were down on their hands and knees helping him 9around the trees. When they were finished, Harry pressed a quarter into each of their hands and said, "I wish I could 10 you more, but it's all I've got right now."

    The girls had often passed his house, and as they 11 on they remembered that the house was always12. No decorations to add cheerfulness were anywhere in sight. Harry sat behind curtain windows, looking 13.

    The quarter in one little girl's palm(手心) seemed to burn a hole of guilt 14 they walked on. The next day she called her friend and they 15 to put their quarters in a jar marked "Harry's Christmas Present". Then they began to seek out small jobs to16more. Every nickel, dime and quarter they earned went into the jar.

    Two days before Christmas, they had enough money to buy new 17and a card. Christmas Eve found them18Harry's doorstep singing carols(圣诞颂歌). When Harry opened the door, they presented him with the gloves wrapped in pretty paper and a19pumpkin pie a mother had just baked. With 20hands he tore open the paper from the gloves, and then to their surprise, he held them to his face and wept.