A fold or pair of folds of the body wall that lines the shell and secretes the substance that forms the shell in mollusks and brachiopods.是什么意思_A fold or pair of folds of the body wall that lines the shell and secretes the substance that forms the shell in mollusks and brachiopods.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句