Plants like duckweeds float on the surface of still and slowmoving waters, while those with roots and flexible stems can stand in swiftflowing streams.是什么意思_Plants like duckweeds float on the surface of still and slowmoving waters, while those with roots and flexible stems can stand in swiftflowing streams.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句