题干

现有如下各说法:
①在水分子中氢、氧原子间以共价键相结合
②活泼金属和活泼非金属化合时一般形成离子键;
③非金属元素间形成的化合物一定是共价化合物;
④根据电离方程式HCl = H+ + Cl,判断HCl分子里存在离子键;
⑤冰的密度比水的密度小,这与氢键有关
上述各种说法正确的是

A:①②⑤

B:①②④⑤

C:①②③④⑤

D:①③④⑤

上一题 下一题 0.0难度 选择题 更新时间:2014-12-12 09:38:16

答案(点此获取答案解析)

A

同类题4

根据短文内容,从短文后的七个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。

Writing A Letter To Your Future Self

    Just imagine writing a letter to your future self 5 years from now, then opening it at that exact moment to see how much of it has come true. ____

    As you read the letter in the future, you can assess how many things agree with your expectations in the past. ____ Often times, the goals we set and our goal achievement process are affected by a lot of changes along the way. The letter lets you recognize how your current idea differs from the past.

    In addition to that, at the very moment you are writing the letter, your thoughts are stored right there in those words. When you open the letter in the future, you as your future self gets to compare how you used to be in the past with how you are now.  ____. It's very interesting to do so.

    Take out a pen and paper right now and start writing your letter to your future self. Set a time period to write to. ____ Then start writing. Think about the type of person you will be, your place in life, what you will have realized then, and so on.

    ____ Put it in a safe space where no one can find it. When you open this sometime in the near future, you might gain additional insights(了解) about yourself and your journey in the past few years.

A. And you can think about why that's the case.

B. It is a useful tool to be used in goal achievement.

C. Imagine how you will be like during that time period.

D. If you haven't, join me in writing a letter to yourself.

E. This lets you see how much things have changed since then.

F. At the end of the letter, write the date to open it on the cover.

G. It wasn't until we moved into our new house that I found it again.