The rooms are crammed with humming Xerox machines.

　　那些房間里擺滿了嗡嗡作響的復印機。

　　Could you xerox this letter, please?

　　請復印一下這封信好嗎？

　　He kept the original copy and gave her only a Xerox.

　　他保留下原件而只給了她一份復印件。

　　Secondary xylem consists of pitted vessels, parenchyma fibers and rays.

　　次生木質(zhì)部由孔紋導管、薄壁組織及射線所組成。

　　The xylem of ferns and conifers contains only tracheids.

　　蕨類植物和針葉樹的木質(zhì)部僅含有管胞。