题干

下列各选项能说明分子式为C4H6的某烃是HC≡C﹣CH2﹣CH3,而不是CH2═CH﹣CH═CH2的事实是(   )

A:燃烧有浓烟

B:能使KMnO4酸性溶液褪色

C:能与溴发生1:2加成反应

D:与足量溴水反应,生成物中只有2个碳原子上有溴原子

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答案(点此获取答案解析)

D

同类题4

阅读材料,回答问题。

材料一:中国的近代是一个多灾多难的百年屈辱史,为了挽救民族危机,实现救亡图存,中国的无产阶级进行了艰辛的探索。中国的无产阶级由于受到帝国主义、官僚资本主义与封建主义三座大山的沉重压迫,反抗压迫的愿望非常强烈;再加上他们是先进生产力的代表,从事着大机器生产,所以其革命具有彻底性;特别是中国的无产阶级政党-***的诞生,具有划时代的重大意义,***领导着中国广大人民,经过几十年的浴血奋战,终于取得了反帝反封的民主革命的胜利!

材料二:关于辛亥革命的评价,历来众说纷纭。有人认为,辛亥革命成功了,因为辛亥革命给封建专制制度以致命的一击。它推翻了统治中国近代长达270多年的腐败屈辱的清王朝,结束了中国两千多年的封建君主专制制度,建立起资产阶级共和国,推动了历史的前进。并且,辛亥革命为民族资本主义的发展创造了有利的条件。民国建立以后,国内实业集团纷纷成立,开工厂、设银行成为风气。民族资本主义的经济力量在短短的几年内就有了显著的增长,无产阶级队伍也迅速壮大起来。也有人认为,辛亥革命没有完成反帝反封的民主革命任务,没有改变中国半殖民地半封建社会的性质,也没有使中国走向富强与统一,反而在辛亥革命后,中国不久就进入了北洋军阀统治的黑暗时期,军阀混战,社会大动荡,生灵涂炭,民不聊生,所以辛亥革命失败了。

同类题5

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

    A boy from a farmer's family stopped from school due to poverty, and went back farming to1the family. When he grew up to 19 years old, his father died. After that, all the family2 him including his mother and grandma in sickness.

    At first, he 3a pool and wanted to feed fish. But others told him it couldn't be used to feed fish, but only to grow crops. What he could do was to cover the pool and thereafter he became a  4.

    Then he heard raising chickens was a way of making money.  He borrowed some money from relatives and  5  chickens.  6  a flood attacked the town, and after that all the chickens got sick and        almost  7. His mother could hardly 8  it and died in the gloom.

    He 9the businesses of making wine, fishing or even digging embrasures (炮眼) on the cliff for others.

    When he was 35, he had no wife, no money, but only lived in a house made from earth which would 10in any storm. But he still wanted to 11 . He borrowed some money to buy a truck. But when he   drove it on the road after a short while, he had an  12  and broke his leg. He became crippled. Everyone said he was  13 .

    But later he became a boss, who owned a capital of 200 million. Now lots of people know his past and his business experiences. A journalist made a(n) 14with him.

    “Why do you  15after so many failures?”

    He was sitting in front of a broad table and just had finished a cup of water. Then he held the16cup in hand and asked, “If I loose my hand, what will happen to this cup?”

    “Broken!” answered the journalist.

    He 17his hand and the cup fell to the floor, with a bang sound, but not 18.

    “Even if ten people were there they would believe it was broken. But, it isn't a(n)  19cup. It is made of  20.”