苯乙醇胺A(C 19 H 24 N 2 O 4 )是瘦肉精品种目录中的一种,与其他瘦肉精品种如菜克多巴胺等相比,同样可使生猪长速加快、皮红毛亮、瘦肉率高.人吃了含有这种瘦肉精的猪肉后,可诱发高血压、心脏病等. (1)苯乙醇胺A中氮元素和氧元素的质量之比为______; (2)苯乙醇胺A的相对分子质量为______; (3)苯乙醇胺A中氮元素的质量分数为______.(保留三位有效数字)
【简答题】阅读理解。 The 26-year-old, Sui Feifei, shines in basketball s. But it is her pretty face that catches her most attention (注意). She is known as 'beauty' on the basketball court (篮球场). Sui Feifei has be...