Pigs in these systems have little or no immunity to normal pathogens. Allowing access of these pathogens has been shown to lead to catastrophic breakdowns.是什么意思_Pigs in these systems have little or no immunity to normal pathogens. Allowing access of these pathogens has been shown to lead to catastrophic breakdowns.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句