题干

实验废液中可能含有离子K+、Mg2+、Cl、Ba2+、SO42、CO32中的几种,为确定可能含有的离子,兴趣小组进行了下面的实验:

①取一份废液,加入氯化钡溶液有白色沉淀产生,再加入足量稀盐酸,沉淀无变化;

②另取一份废液,加入氢氧化钾溶液出现白色沉淀,再加入足量稀盐酸,沉淀全部溶解,

分析上面实验得出的结论中,正确的是(  )

A:只含有Mg2+、SO42

B:一定含有K+、Mg2+、Cl、SO42

C:一定含有Mg2+、SO42,可能含有Cl、K+

D:一定含有Cl、K+,可能含有Mg2+、SO42

上一题 下一题 0.0难度 选择题 更新时间:2018-08-05 05:10:44

答案(点此获取答案解析)

C

同类题1

根据短文内容, 从短文后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。

    Too many of us are waiting too long to live our best lives. We keep putting everything off until tomorrow. Then, before we know it, we find ourselves asking, "How did it get so late so soon?"

    So we'd better make today the beginning of our new life. Take time to realize what we want and need. Take time to love, laugh, cry, and learn. ____ Here are five things we should start doing today:

    Accept ourselves. The secret to happiness and success is the acceptance of ourselves. We will never become who we want to be if we rely on everyone else to qualify us.____ So always go with ourselves, never against ourselves. Be who we were created to be and we will set the world on fire.

    Make ourselves a priority. To tell the truth, there are only a few people in this world who will stay 100% true to us, so we should stay true to ourselves. Put our own needs into the list of things to do.

    ____ Don't sit back and let things happen to us. Go out and make things happen. We are what we do, not what we say we'll do. Stop saying "I wish" and start saying "I will". Turn our dreams into plans.

    Do the work. We can't underestimate(低估) a person who always works hard. Be that person.____ Always remember that the task ahead of us is never greater than the strength within us. Do what's right, not what's easy. Our dreams are worth it.

    ____ We can't force things to happen; we can only drive ourselves trying crazily. There's a time and place for everything. So don't force what's not yet supposed to fit into our life. When it's meant to be, it will be. Work hard, and be patient.

A. Take positive action.

B. Enjoy every moment of life.

C. Life is shorter than it often seems.

D. Everyone has a different way of life.

E. Accept ourselves just the way we are.

F. Allow life to happen like it's supposed to.

G. In life, we don't get what we wish for; we get what we work for.