This says that there can not have been battery acid strength acid rain at the end of the Cretaceous.

这就说明在白垩纪晚期没有出现像电池酸那样强的酸雨。

The pH scale is the most common way of measuring an acid's strength, based on the concentration of active hydrogen ions when the acid is mixed with water.

pH 值是衡量酸性强弱最常用的一种方法，根据酸在水溶液中的活泼氢离子浓度进行计算。