题干

把下列四种X溶液分别加入四个盛有10mL 2mol/L盐酸的烧杯,均加水稀释到50mL,此时,X和盐酸缓慢地进行反应,其中反应最快的是

A:20℃30mL 2mol/L的X溶液

B:10℃20mL 3mol/L的X溶液

C:20℃10mL 4mol/L的X溶液

D:10℃10mL 2mol/L的X溶液

上一题 下一题 0.0难度 选择题 更新时间:2019-03-09 12:33:23

答案(点此获取答案解析)

A

同类题2

阅读下文,完成问题。

傅雷家书一封

    亲爱的孩子,你回来了,又走了;许多新的工作,新的忙碌,新的变化等着你,你是不会感到寂寞的;我们却是静下来,慢慢地恢复我们单调的生活,和刚过去的欢乐与忙乱对比之下,不免一片空虚,——昨儿整整一天若有所失。孩子,你一天天地在进步,在发展。这两年来你对人生和艺术的理解又跨了一大步,我愈来愈爱你了,除了因为你是我们身上的血肉所化出来的而爱你以外,还因为你有如此焕发的才华而爱你:正因为我爱一切的才华,爱一切的艺术品,所以我也把你当作一般的才华(离开血肉关系),当作一件珍贵的艺术品而爱你。你得千万爱护自己,爱护我们所珍视的艺术品!遇到任何一件出入重大的事,你得想到我们——连你自己在内——对艺术的爱!不是说你应当时时刻刻想到自己了不起,而是说你应当从客观的角度重视自己:你的将来对中国音乐的前途有那么重大的意义。你每走一步,无形中都对整个民族艺术的发展有影响,所以你更应当战战兢兢,郑重其事!随时随地要准备牺牲目前的感情,为了更大的感情——对艺术对祖国的感情。你用在理解乐曲方面的理智,希望你能普遍的应用到一切方面,特别是用在个人的感情方面。我的园丁工作已经做了一大半,还有一大半要你自己来做了。爸爸已经进入人生的秋季,许多地方都要逐渐落在你们年轻人的后面,能够帮你的忙将要越来越减少,一切要靠你自己努力,靠你自己警惕,自己鞭策。你说到技巧要理论与实践结合,但愿你能把这句话用在人生的实践上去,那么你这朵花一定能开得更美,更丰满,更有力,更长久!

    谈了一个多月的话,好像只跟你谈了一个开场白。我跟你是永远谈不完的,正如一个人对自己的独白是终生不会完的。你跟我两人的思想和感情,不正是我自己的思想和感情吗?清清楚楚的,我跟你的讨论与争辩,常常就是我跟自己的讨论与争辩。父子之间能有这种境界,也是人生莫大的幸福。除了外界的原因没有能使你把假期过得像个假期以外,连我也给你一些小小的不愉快,破坏了你回家前的对家庭的期望。我心中始终对你抱着歉意。但愿你这次给我的教育(就是说从和你相处而反映出我的缺点)能对我今后发生作用,把我自己继续改造。尽管人生那么无情,我们本人还是应当把自己尽量改好,少给人一些痛苦,多给人一些快乐。说来说去,我仍抱着“宁天下人负我,毋我负天下人”的心愿。我相信你也是这样的。

同类题4

根据短文内容,从短文后面的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

    What should you think about in trying to find your career(职业)? You are probably better at some school subjects than others. ____ A boy who is good at mathematics can use that in an engineering career. ____ So it is important to do well at school. On the other hand, you may not have any specially strong or weak subjects but your records show a general satisfactory standard. ____ Knowledge of history is not required for most jobs but if history is one of your good subjects you will have learned to remember facts and details. This is an ability that can be useful in many jobs.

    ____ If nothing else, you may have learned how to get to work on time, to follow instructions and to get on with older workers. Just as important, you may become interested in a particular industry or career you see from the inside in a part-time job.

    Facing your weak points is also part of knowing yourself. ____ Your school record, for instance, may not be too good, yet it is an important part of your background. You should not be apologetic about it but instead recognize that you will have a chance of a fresh start at work.

A. It is better to face any weaknesses than to pretend they do not exist.

B. A girl who spells well and likes English may be good at office work.

C. He may do well in his future work.

D. Although not all subjects can be used directly in a job, they may have indirect value.

E. Your school must have taught you the skills.

F. These may show strengths (优势) that you can use in your work.

G. If you have had a part-time job on Saturday or in the summer, think what you gained from it.