People wrote letters to get in touch in the past. Nowadays email has       the way people communicate.

A．directed

B．conveyed

C．transformed

D．sponsored

脱位的正确定义是

A．关节自关节囊内突出
B．关节囊发育不良导致关节失去稳定性的现象
C．关节面失去正常的对合关系
D．组成关节的关节面部分失去对合关系
E．组成关节的各关节面失去正常的啮合关系