In 20 grade 1 ulcers (92%), no virulence genes were identified whereas these genes were present in all but one grade 2-4 ulcers.是什么意思_In 20 grade 1 ulcers (92%), no virulence genes were identified whereas these genes were present in all but one grade 2-4 ulcers.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句