题干

向硝酸银、硝酸铜、硝酸镁的混合溶液中加入一些铁粉,待充分反应后,再过滤.下列情况不可能存在的是(   )

A:滤纸上有银,滤液中有Cu2+、Ag+、Fe2+、Mg2+

B:滤纸上有Cu、Ag,滤液中有Fe2+、Mg2+

C:滤纸上有Cu、Ag,滤液中有Ag+、Fe2+、Mg2+

D:滤纸上有Fe、Cu、Ag,滤液中有Fe2+、Mg2+

上一题 下一题 0.0难度 选择题 更新时间:2017-12-06 02:25:37

答案(点此获取答案解析)

C

同类题3

短文填空。从下面方框中选出10个单词,使短文意思正确通顺(每词限用一次)。

fight  they  for  suggest  healthy  if  fan  depend  lonely  what  cause  how

    One night, lots of people were running through the streets, shouting and throwing rocks. It was all about a soccer game. They were soccer ____ and they were angry that their team had lost an important game. They went completely out of control

    It's common ____ fans to get crazy. So many cities choose to put more police officers on the streets after big games. ____ makes fans so crazy?

    Some experts believe it goes back to a long-ago time when humans lived in tribes (部落). These tribes ____ each other for food, land and power (权力). You supported your tribe's warriors (武士) because your life ____ on them.

    Today's“warriors” are athletes (运动员). Cheering for ____ can bring out the same life-or-death feelings. That can be exciting and fun. It also ____ problems if the strong feelings last (持续) hours or days after a game has ended.

    On the other hand, some people say that being a sports fan can make you a happier and ____ person. Research shows that if you have a strong connection to a team, you might make strong connections with people. Many fans feel a sense of belonging to a group. They are less ____ and have more enjoyable social lives.

    ____ your favorite teams make you a bit crazy sometimes, it's only because you love them. And that's good — if you can remember that it's only a game.

同类题4

阅读下面的文言文语段,完成小题。

        【甲】舜发于畎亩之中,傅说举于版筑之间,胶鬲举于鱼盐之中,管夷吾举于士,孙叔敖举于海,百里奚举于市。故天将降大任于是人也,必先苦其心志,劳其筋骨,饿其体肤,空乏其身,行拂乱其所为,所以动心忍性,曾益其所不能。人恒过,然后能改;困于心,衡于虑,而后作;征于色,发于声,而后喻。入则无法家拂士,出则无敌国外患者,国恒亡。然后知生于忧患,而死于安乐也。

        【乙】任末(人名)年十四时,学无常师,负笈(书籍)从师,不惧险阻。每言:“人而不学,则何以成?”或依林木之下,编茅为庵,削荆为笔,刻树汁为墨。夜则映星望月,暗则缕麻蒿以自照。观书有合意者,题其衣裳,以记其事。门徒悦其勤学,更以静(通“净”)衣易之。临终诫曰:“夫人好学,虽死犹存不学者虽存谓之行尸走肉耳!”

                                                                                                                                                                                                                       (选自王嘉《拾遗记》)