题型:操作题 I heard a new book by professor Li has been ____. Shall we go and have a look in the bookshop?A. publishing B. published C. printed D. printing 查看答案
题型:操作题 近年来,乳酸成为人们研究的热点之一,乳酸在医药、食品等工业中应用前景广阔。乳酸的化学式为C3H6O3,试计算:(1)乳酸分子的相对分子质量;(2)乳酸中碳、氢、氧元素的质量比;(3)乳酸中碳元素的质量分数。 查看答案