—— I've found a wallet at the gate. is it? —— Oh, it's mine.
A:Where
B:What
C:Whose
3D打印技术具有划时代意义,目前国际上已有包括动脉和肾脏等打印成功的案例。只要在患者身上取一些干细胞培养成打印原料,就可以打印出一模一样的器官进行移植。这说明( )
下面是同学们分组测量牛奶密度的实验过程,请你将实验过程补充完整.