proportion by weight短语¹⁴⁴⁹⁷²⁺² 基本例句 重量比 The strength of the cement is low, the stability of volume is unqualified, primarily is to go together with raw materials mix proportion by weight what caused by inappropriate reasons. 水泥的强度低，安定性不合格，主要是配料不当的原因造成的。 chemyq