[单项选择]

For (1) service, we need a virtual-circuit subnet. Let us see how that works. The idea behind virtual circuits is to avoid having to choose a new  (2) for every packet sent. Instead, when a connection is established, a route from the  (3) machine to the destination machine is chosen as part of the connection setup and stored in tables inside the (4) .That route is used for all traffic flowing over the connection, exactly the same way that the telephone system works. When the connection is released, the virtual circuit is also terminateD. With connection-oriented service, each packet carries an  (5) telling which virtual circuit it belongs to.

空白（1）处应选择（）
A. connectionless
B. connection-oriented
C. datagram
D. telegram

[单项选择]

For (1) service, we need a virtual-circuit subnet. Let us see how that works. The idea behind virtual circuits is to avoid having to choose a new  (2) for every packet sent. Instead, when a connection is established, a route from the  (3) machine to the destination machine is chosen as part of the connection setup and stored in tables inside the (4) .That route is used for all traffic flowing over the connection, exactly the same way that the telephone system works. When the connection is released, the virtual circuit is also terminateD. With connection-oriented service, each packet carries an  (5) telling which virtual circuit it belongs to.

空白（2）处应选择（）
A. processor
B. device
C. route
D. terminal

[单项选择]Our aim was to update the health service and we succeeded.
　　


A. offer
B. provide
C. modernize
D. fund

[单项选择]（）we need air and water, so do we need criticism and self-criticism.
A. Even though
B. So long as
C. Just as
D. Now that

[单项选择]We need one hundred more signatures before we take the ______ to the governor.
A. panel
B. kernel
C. petition
D. paragraph

[单选题]We are in charge of aeronautical information service and we provide _______ to all flight crews.
A.flight NOTAM bulletins
B.post-flight briefing
C.AIP manual
D.en-route flight controls

[简答题]Why Do We Need English

[单项选择]______ we need air and water, so do we need criticism and self-criticism.


A. Even though
B. So long as
C. Just as
D. Now that

[简答题]Once we have accomplished one thing, we need to remember that there is plenty left to do. The feeling that we are always aiming for new goals, always on the brink (边缘) of doing something new and exciting, makes it easier for us to tackle new challenges with enthusiasm. Of course we have the right to feel satisfied occasionally, but not for too long, otherwise this sense of satisfaction will keep us from moving forward.

[多项选择]

Do We Need Unified School Uniforms

[单项选择]We need a chairman （）.
A. for whom everyone has confidence
B. in whom everyone has confidence
C. who everyone has confidence of
D. whom everyone has confidence on

[单项选择]We need to make sure that we ______ our resources as fully as possible.
A. use
B. exploit
C. employ
D. explore

[单项选择]

We need to conduct extensive background research on the firms from（）we received bids.
 

A. which
B. where
C. that
D. when

[单项选择]We need to consider what ______ we will be using for language training.
A. abilities
B. appliances
C. facilities
D. qualities

[单项选择]______ the wall, we decided that we should need three tins of paint.
A. Making up
B. Doing up
C. Putting up
D. Sizing up.