Mount Vernon is a city of south-central Illinois east-southeast of East St. Louis. It is a trade and industrial center in a farming region. Population,16,988.是什么意思_Mount Vernon is a city of south-central Illinois east-southeast of East St. Louis. It is a trade and industrial center in a farming region. Population,16,988.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句