单选题
Password is a secret series of {{U}} {{U}}
73 {{/U}} {{/U}}that enables a user to access a file, computer, or
program. On multi-user systems, each user must enter his or her password before
the computer will respond to {{U}} {{U}} 74 {{/U}} {{/U}}. The
password helps ensure that {{U}} {{U}} 75 {{/U}} {{/U}}users do
not access the computer. In addition, data files and programs may require a
password.