An auxin increases the growth in length of a plant cell, thus causing the curving of a stem, or roof, in phototropism and geotropism.是什么意思_An auxin increases the growth in length of a plant cell, thus causing the curving of a stem, or roof, in phototropism and geotropism.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句