题干

如图所示图象能正确反应其对应的实验操作的是(  )

A:一定温度下,向饱和的硝酸钾溶液中不断加入硝酸钾固体

B:向硫酸和硫酸铜混合溶液中滴加过量的氢氧化钠溶液

C:将等质量的镁粉和铝粉分别与足量等浓度的稀硫酸反应

D:向盛有一定量稀硫酸的烧杯中不断加水稀释

上一题 下一题 0.0难度 选择题 更新时间:2019-01-28 02:16:40

答案(点此获取答案解析)

B

同类题4

阅读下面短文, 从短文后各题所给的四个选项(A、B、C、D)中, 选出可以填入空白处的最佳选项。

    If you want to learn a new language, the very first thing to think about is why. Do you need it for a 1 reason, such as your job or your studies? 2perhaps you are interested in the 3, films or the music of a different country and you know how much it will help to have a 4 of the language.

    Most people learn best using a variety of 5, but traditional classes are an ideal(理想的)start for many people. They 6 an environment where you can practice under the 7 of someone who's good at the language. We all lead 8 lives and learning a language takes 9. You will have more success if you study regularly, so try to develop a 10. It doesn't matter if you haven't got long. Becoming fluent in a language will take years, but learning to get by takes 11.

    Many people start learning a language and soon give up. “I'm too 12,” they say. Yes, children do learn languages more 13 than adults, but research has shown that you can learn a language at any 14. And learning is good for the health of your brain, too. I've also heard people 15 about the mistakes they make when 16. Well, relax and laugh about your mistakes 17you're much less likely to make them again.

    Learning a new language is never 18. But with some work and devotion, you'll make progress. And you'll be 19by the positive reaction of some people when you say just a few words in 20 own language. Good luck!