企业征信系统中，报文预处理子系统能对报文格式进行（）操作。
A.校验
B.加密加压
C.拆分
D.解密解压
参考答案：A, C, D
— How unhappy your roommate looks!
— Yes, but he's not willing to tell me what it is ____ is troubling him. [ ]
A. what
B. which
C. as
D. that
冲裁时板料分离的变形过程可分为哪些阶段？
