常見(jiàn)例句The xylem of ferns only contains tracheids.蕨類(lèi)植物的木質(zhì)部只含有管胞。It is found in protoxylem and first metaxylem tracheids and vessels.可在原生木質(zhì)部和初始后生木質(zhì)部的管胞和導(dǎo)管中見(jiàn)到。 返回 tracheids