题干

下列物质露置于空气中,因发生化学变化而使其总质量增加的是(     )

A:食盐水   

B:烧碱溶液   

C:浓盐酸   

D:浓硫酸

上一题 下一题 0.0难度 选择题 更新时间:2016-10-10 07:58:05

答案(点此获取答案解析)

B

同类题4

阅读毕淑敏《读书使人优美》一文(略有改动),完成问题。

      ①优美在字典上的意思是:美好。

      ②做一个美好的人,我相信是绝大多数人的心愿。谁不愿意美好啊?除了心灵的美好,外表也需美好。为了这份美好,人们使出了万千手段。比如刀兵相见的整容,比如涂脂抹粉的化妆。为了抚平脸上的皱纹,竟然发明了用肉毒杆菌的毒素在眉眼间注射,让面部微小神经麻痹,换来皮肤的暂时平滑……让我这个曾经当过医生的人,胆战心惊。

      ③其实,有一个最简单的美容之法,却被人们忽视,那就是读书啊!

      ④读书的时候,人是专注的。因为你在聆听一些高贵的灵魂自言自语,不由自主地谦逊和聚精会神。即使是读闲书,看到妙处,也会忍不住拍案叫绝……长久的读书可以使人养成恭敬的习惯,知道这个世界上可以为师的人太多了,在生活中也会沿袭洗耳倾听的姿态。而倾听,是让人神采倍添的绝好方式。所有的人都渴望被重视,而每一个生命也都不应被忽视。你重视了他人,魅力就降临在你双眸。

      ⑤读书的时候,常常会会心一笑。那些智慧和精彩,那些英明与穿透,让我们在惊叹的同时拈页展颜。微笑是最好的敷粉和装点,微笑可以传达比所有语言更丰富的善意与温暖。有人觉得微笑很困难,以为是一个如何掌控面容的技术性问题,其实不然。不会笑的人,我总疑心是因为读书的不够广博和投入。书是一座快乐的富矿,储存了大量浓缩的欢愉因子,当你静夜抚卷的时候(当然也包括网上阅读),那些因子如同香氛蒸腾,迷住了你的双眼,你眉飞色舞,中了蛊似的笑起来,独享其乐。也许有人说,我读书的时候,还时有哭泣呢!哭,其实也是一种广义的微笑,因为灵魂在这一个瞬间舒展,尽情宣泄。告诉你一个小秘密:我大半生所有的快乐累加一处,都抵不过我在书中得到的欢愉多。而这种欣悦,是多么的简便和利于储存啊,物美价廉,重复使用,而且永不磨损。

      ⑥读书让我们知道了天地间很多奥秘,而且知道还有更多的奥秘,不曾被人揭露,我们就不敢用目空一切的眼神睥睨天下。读书其实很多时候是和死人打交道,图书馆堆积的基本上是哲人的木乃伊,书店里出售的大部分是亡灵的墓志铭。你在书籍里看到了无休无止的时间流淌,你就不敢奢侈,不敢口出狂言。自知是一切美好的基石。当你把他人的聪慧加上你自己的理解,恰如其分地轻轻说出的时候,你的红唇就比任何美丽色彩的涂抹,都更加光艳夺目。

      ⑦你想美好吗?你就读书吧。不需要花费很多的金钱,但要花费很多的时间。坚持下去,持之以恒,优美就像五月的花环,某一天飘然而至,簇拥你颈间。

同类题5

阅读下列短文, 根据要求完成下列各题。

      Have you heard about “Survival (生存) Holidays”? “Survival Holidays” is for children to go into the lonely place for exciting activities. Now about 1,100 companies are allowed to(被允许) take children into the great outdoors without their parents.

      The reason why people like “Survival Holidays” is that they think being close to nature is good for children. Many children in big cities spend all time watching TV and playing computer games. “Survival Holidays” gives them an important change.

      Is “Survival Holidays” a wonderful idea? Maybe it is. Children need more free time to play. They need to be left on their own, without adults(成年人) disturbing (打扰) them. Parents care too much about their children. They like to see the children being busy with activities that are controlled by adults, but children don’t know what to do when they are in danger. Even something like crossing a small river seems to be a hard challenge. Children are not comfortable with danger. Even small danger like getting their feet wet or falling down seems very terrible to them.

      Many people think the survival activities are good for children. Even years later, they will still remember what they have learned. Some have learned to stay calm in different times. Some have learned how to keep safe. Others have learned how to work in a team. All these skills will help them a lot in their lives.