题目

阅读理解Noone ever said science education was easy. Certainly the concepts we teach, likeconservation of momentum (动量守恒) orquantum mechanics (量子力学)，can behard to grasp. But what really makes our reaching complicated is that we'realso trying to teach a deeper lesson at the same time — to help studentsunderstand the nature of science itself.Alltoo often, young people get the impression that science is about learningcertain laws and then applying them to different situations. Afterall, that's what we make them do on tests, to show that they've been doing thework. But that'某组成为CaHbNc（a、b、c为正整数）的ABS工程树脂可通过下面的反应制得：C3H3N+C4H6+C8H8CaHbNc（未配平）丙烯腈    1，3-丁二烯   苯乙烯            ABS则参加反应的原料中丙烯腈和1，3-丁二烯的分子个数之比为（ ）A．B．C．D．无法确定