The professor walked onto the platform a

下列动物中不属于鸟类的是（　　）

A．家鹅

B．孔雀

C．蝙蝠

D．猫头鹰

从方框中选择恰当的词或短语并用其正确的形式填空。

小题1:The boy ____________________________ English now.

小题2:She is not asleep. She is _________________.

小题3:Eating healthy food ________________________ our health.

小题4:If we give the job to the man, it is ________________ for the woman.

小题5:She always buys me some gifts __________ when I am in a bad mood.

小题6:It is important ________________________ before you begin to do it.

小题7:You had better wear white when you are _________________________.

小题8:The old man ______________________________________ last year.

小题9:The poor girl often _____________________ her mother after her mother died.

小题10:I go to school by bike ________________.

中医“切脉”时，按摸到的血管所具有的特点是[ ]

A．管壁薄、弹性小、血流慢

B．管壁厚、弹性大、血流快

C．管壁极薄、血流最慢

D．管腔大、血流快

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（4）处应选择（）

A.connections

B.resources

C.bridges

D.routers

男，18岁。运动员常规体检时心电图示心室率50次／分。P-R间期0.21s，P-R间期及R-R间期恒定不变，QRS波群形态和时限正常。最可能的诊断为（）

A.二度Ⅰ型房室传导阻滞

B.二度Ⅱ型房室传导阻滞

C.三度房室传导阻滞

D.心房颤动伴差异性传导

E.一度房室传导阻滞