polio-freeCOCA³¹⁵¹¹¹⁺⁴Economist³⁴³¹⁸⁺³ 基本例句 🌏无脊髓灰质炎 Laboratory stocks must be contained and safe management of the wild virus in inactivated polio vaccine IPV manufacturing sites must be assured before the world can be certified polio-free. 在认证全球无脊髓灰质炎之前，必须控制实验室库存，并确保妥善管理灭活脊灰病毒疫苗 IPV生产地点的野生病毒。 who