A:Look at your skirt
B:How is your skirt
C:What color is your skirt
晁衡是唐朝的外国留学生,也是李白、王维的亲密朋友,他是( )
将200g石灰石与足量的盐酸反应,共收集二氧化碳66g.求:该石灰石中CaCO3的质量分数多少?