题干

某无色溶液中滴入酚酞试液显红色,该溶液中可以大量共存的离子组是

A:Mg2、Al3+、HCO3、SO32

B:K、Ca2、MnO4、Cl

C:Ba2、Na、AlO2、NO3

D:NH4、Fe3、SO42、SCN

上一题 下一题 0.0难度 选择题 更新时间:2014-07-03 03:15:15

答案(点此获取答案解析)

C

同类题2

阅读短文,下列问题

     Do you know what Oscar is? When did it start? Maybe you can find the background of the awards in the following passage.

The awards started in 1929. Their full title is “The Academy of Motion Picture Arts and Sciences Awards”. The Academy is a group of people who have worked in the film industry for many years. They decide who will receive the awards. The awards are often referred to as the “Oscar”. This is a nick name given to the awards by a lady called Margaret Herrick. She was once the director of the Academy and she once said that the little gold statue reminded her of her uncle Oscar!

    The Oscar is always an exciting event. Each year, at least one unusual thing happens. When the Italian actor and director Roberto Benigni won an Oscar for best foreign film, he danced on stage! When Gwyneth Paltrow,the star of Shakespeare in Love won the Oscar for best actress, she could not make her acceptance speech because she was crying so much with happiness!

    In 1987, Roberto Benigni won the award for best director for a film about the last emperor of China. Since then, Chinese film and actors have started to make an impact at the awards. Crouching Tiger, Hidden Dragon was a huge success and it won the award for best foreign language film in 2001.It also won several technical awards for its amazing “flying” people. We expect to see more awards for Chinese film in the near future.

    It's time for the Oscar again. Once more, the stars will dress up in their finest and go to Kodar Theater. There, they will find out who have won the awards for best actor, best actress and best director. Millions of people watch the awards every year to find out who the winners are. Some people watch it to see the stars crying and laughing as they receive their awards.

同类题3

根据材料内容,选择正确答案。


    One day a man found a cocoon(茧) of a butterfly in the forest. He sat there for several hours and watched the butterfly. Suddenly a small opening appeared, and the butterfly made its great effort to force its body through that little hole. Then it seemed to stop making any progress. It appeared as if it had gotten as far as it could and it could go no further.

    So the man decided to help the butterfly. He cut off the remaining bit of the cocoon so that the butterfly could come out easily. But to his surprise, the butterfly got a heavy body and very small wings when it came out of the cocoon.

    The man continued to watch the butterfly because he expected that the body would grow smaller at any moment and the wings would become larger and be able to fly. But neither happened! In fact, the butterfly spent the rest of its life crawling(爬) around with a heavy body and small wings. It was never able to fly.

    The man was in his kindness, but he did not understand the nature rules. Before the butterfly came out of the cocoon, fluid(流体) from its body must be forced into its wings, and then it would be ready for flying. It must have a hard struggle(拼搏) to get through the small opening to get its freedom from the cocoon.

    Sometimes struggles are exactly what we need in our life. If God allowed us to go through our life without any difficulties, it would make us fail. We would not be as strong as we could have been, we could never fly.