操作系统（Operation System,简称OS)是管理计算机硬件与软件资源的计算机程序。（)

A full-scale security operation __________ (现在正在实施之中).

Most Korean young people go to get operation on their______.

A．lips

B．nose

C．eyes

D．breasts

A．Dialogue improves the operation of a team. continuously.

B．Dialogue changes people's old pattern of interaction.

C．Dialogue helps improve the communication of people.

D．Dialogue changes people's perspective.

A) operation

B) position

C) motion

D) location

How does the author indicate oncogenes？

A．They are always in operation in a healthy person.

B．They remain unharmful so long as they are not activated.

C．They can be driven out of normal cells.

D．Normal cells can't turn them off.

A.To make the railway operation safer.

B.To offer passengers more comfortable journeys.

C.To meet the demand of shipping larger loads.

D.To connect the railway network with the highways.

A．Y

B．N

C．NG

A．are less restricted in operation

B．are less flexible

C．are larger shipments

D．are most flexible

How did the immigrants in Salt Lake City feel about "Operation Safe Travel"？

A．Guilty.

B．Offended.

C．Disappointed.

D．Discouraged.

Undocumented workers became the target of "Operation Safe Travel" because ______.

A．evidence was found that they were potential terrorists

B．most of them worked at airports under threat of terrorist attacks

C．terrorists might take advantage of their illegal status

D．they were reportedly helping hide terrorists around the airport