成活率的英文：
rate of survival
survival ratio
survival percent
percentage of success

• cumulative rating
  累积收听率
• These bonds have an AAA rating.
  这些债券的信用度是3A级的。
• To rate too low;underestimate.
  低估对…估价太低；低估

• Few survived after the flood.
  洪水后极少有人生还。
• These are the survivals from the primitive society.
  这些是原始社会的遗物。
• Britain survives free.
  自由在英国得以幸存。

• neutralization ratio
  中和比率|中和比例
• This is the prime ratio of the nascent increments
  这是最初增量的最初比。
• Asset quality ratios: Ratios that measure the quality of assets of a lending institution.
  资产质量比率:衡量贷款机构资产质量的各种比率。