Mr.White works in an import and export c

采用心室面积轴线缩短法判断左心室室壁运动异常的缩短率标准是()

A．<5%

B．<10%

C．<10%

D．<20%

E．<30%

1934年10月，中 * * 和中央红军进行长征的主要原因[ ]

A．第五次反“围剿”的失败

B．开辟新的革命根据地

C．北上抗日

D．进一步把革命推向全国

一日三餐中，中、晚餐都很重要，早餐少吃一点或不吃没多大关系。

某人血浆中含有抗A，抗B凝集素，则此人的血型可能是（）。

A.A1型

B.B型

C.AB型

D.A2B型

E.O型

Both bus and tree topologies are characterized by the use of multipoint （1）. For the bus, all stations attach, through appropriate hardware （2）known as a tap, directly to alinear transmission medium, or bus. Full-duplex operation between the station and the tap allowsdata to be transmitted onto the bus and received from the （3）. A transmission from anystation propagates the length of the medium in both directions and can be received by all other（4）. At each end of the bus is a （5）, which absorbs any signal, removing it from thebus.

（5）是（）

A.tap

B.repeat

C.terminator

D.concentrator