Smith was overweight, so the doctor urged that not only _______ have less fat and meat,but also he _______.

A．should he; take exercise

B．must he; takes exercises

C．he can; does some exercises

D．he ought to; do some practice

用于识别客户身份的信息有哪些（）。

A.源系统编号

B.客户名称

C.证件号码

D.证件类型