根据农村社会群体形成的直接原因，可将其划分为五种类型

油脂通常存在形式为（　　）

A．固态

B．液态

C．气态

D．固态和液态

市场营销预测

什么是滑参数停机？

下列关于期权和期货的区别正确的是( )。

A．期权和期货的交易双方都可将协议转让
B．期货的交易双方都要缴纳保证金，而期权仅卖方需缴纳保证金
C．期权和期货的交易双方在协议有效期内，双方都要为对方承担义务
D．期权交易的双方在签约或成交时双方不发生任何经济关系，而期货交易的双方在签约成交时，买方需向卖方缴纳费用

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.

（4）是（）

A.routers

B.stations

C.servers

D.switches