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使用化学制剂如稀醋、稀柠檬汁或浓盐水放入阴道,是最古老的避孕方法。专卖的杀精子剂直到三十年代才得以通用。此后杀精子剂的使用不断增
Using chemicals such as thin vinegar, lemon juice or concentrated salt water into the vagina is the oldest method of contraception. Monopoly spermicide was not until the 1930s universal. Since then the use of spermicides has been increasing