题干

下列归纳和总结完全正确的一组是(   )

A.对除杂的认识

B.鉴别的方法

①用化学方法除去食盐水中可溶性杂质

②用磁铁除去铁粉中木炭粉

③用碳酸钠除去CaCl2溶液中的HCl

①用燃着的木条鉴别氧气和二氧化碳

②用熟石灰区别化肥硝酸钾和硝酸铵

③用酚酞试液鉴别稀盐酸和氯化钠溶液

C.对现象的认识

D.化学学与贡献

①花香四溢,说明分子在不断运动

②镁条燃烧,有大量白雾产生

③电解水生成氢气和氧气的体积比为2:1

①拉瓦锡﹣发现空气的主要成分

②门捷列夫﹣发现元素周期表

③侯德榜﹣发明联合制碱法

A:A  

B:B  

C:C  

D:D

上一题 下一题 0.0难度 选择题 更新时间:2019-11-13 07:09:48

答案(点此获取答案解析)

D

同类题5

阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项。

(A)

    Yi Jianlian is a popular Chinese basketball player. He entered CBA at the age of 15. In 2005, he became the youngest MVP winner of CBA. From 2007 to 2012, he played in the NBA and spent five seasons there. Now, he will go back to the NBA. He signed a one-year deal(合约) with the Los Angles Lakers.

    He did a good job and that helped him win the honor again. In the Rio Olympic Games, he averaged 20.4 points for China in five games.

 



    You may take buses every day, but do you ever think about painting buses? In Washington, the US, there is such an activity for students. People hold it every year. Last year, it was on Aug.17. Students from 13 high schools competed to paint buses. The buses came from school, churches and some bus companies.

    Last year, the final winner was Avella High School. They painted their bus black with lighter paint to make it look like space. There are many Star Wars characters on the sides of the buses.


    While many Chinese students go abroad to learn Western culture, foreign students come to China. They get close to traditional Chinese culture. This summer,55 students and teachers from Germany came to China and joined a summer camp. They visited several schools in Hefei, Anhui. There they tried to make dumplings and learn calligraphy(书法). To help them know more about China, Chinese students played with them as partners. They led these foreign guests to places of interest.