桂枝去芍药汤，去芍药的理由是（）
A.未伤津液
B.无腹痛
C.有碍宣通阳气
D.更利于解表
E.无需调和营卫
参考答案：C
— How long have you been collecting shells?
— ______.
A．After I left school
B．Before I moved here
C．When I went to the beach
D．Since I was ten years old
邮政编码是由6位数字组成的字符串，为邮政编码设置输入掩码，正确的是。
A．0
B．999999
C．CCCCCC
D．LLLLLL
