题型:问答题 简答题 近年来,乳酸成为人们研究的热点之一,乳酸在医疗、食品工业中应用前景广阔.已知乳酸的化学式C3H6O3,试计算:(1)乳酸(C3H6O3)分子中碳、氢、氧原子个数比______;(2)乳酸(C3H6O3)中碳、氢、氧三种元素的质量比______;(3)从分子角度,C3H6O3表示的意义为______(任写一条). 查看答案
题型:问答题 简答题 One-child policy has ______ controlling China’s population.A. did well in B. worked well in. C. worked good in 查看答案