英语语法分析

Kanendomycin is a very stable antibiotic, and its activity does not decrease when the powder is placed in an airlight container and kept at room temperatures for more than 2 years.

卡内多霉素是一种很稳定的抗生素，其粉沫置于密封容器中，在室温下保存二年以上，活性不减。