工程咨询单位进行自身组织设计，应考虑的因素主要有( )等。A．项目管理特点 B．市

I learned ______ the violin when l was 4 years old.[ ]

A.  played    

B.  to play    

C.  to playing  

D.  play

全身骨显像图中出现甲状腺和胃的影像可能是下列何种因素所致（）。

A.放射性核素不纯

B.显像剂中存在游离的高锝酸盐

C.显像剂中存在还原剂

D.骨骼系统存在转移性疾病

E.存在放射性污染

根据进度计划安排在某一确定时间内所应完成的工程内容的施工成本是（）。

A．已完工程计划施工成本

B．未完工程计划施工成本

C．已完工程实际施工成本

D．未完工程实际施工成本

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.

（2）是（）

A.processing

B.switching

C.routing

D.interfacing