Password is a secret series of (73) that
题型：单项选择题
问题：
Password is a secret series of (73) that enables a user to access a file，computer,orprogram．On multi—user systems，each user must enter his or her password before the computerwill respond to (74) ．The password helps ensure that (75) users do not access the computer．In addition，data files and programs may require a password．
A．symbol
B．sign
C．characters
D．characteristic
面宽度