—The sweater is _______ for me, Dad.—Well, let's buy a big one this afternoon.
莽草酸是我国传统香料,其化学式为:C7H10O5,试计算:
①莽草酸分子的相对分子质量____.
②莽草酸中碳、氢、氧元素质量比为____.
③34.8g莽草酸中含有____g碳元素.