molecular mass的用法和样例：
例句
- The influence of solvents,molecular weight and the content of polyethersulfone on the membrane performances was studied.
研究了聚醚砜的溶剂和相对分子质量及含量对膜性能的影响。 - The structural formula, including relative and absolute stereochemistry, the molecular formula, and the relative molecular mass should be provided.
应当提供结构分子式，包括相对和绝对立体化学分子式，分子式，相对分子质量等。
