( ) is generally accepted, L/C must be es
题型：单项选择题
问题：
( ) is generally accepted, L/C must be established 15 days before shipment.
A．It
B．As
C．That
D．What
( ) is generally accepted, L/C must be established 15 days before shipment.
A．It
B．As
C．That
D．What