在实践中，当事人意思表示非自愿、不真实的情况主要包括( )。 A．一方以欺诈、胁迫

I am a League member. I volunteer my time ___________ others.

A．help

B．to help

C．helping

D．helped

—Will there be an English test next Monday?      

—No, ________.       [ ]

A. there isn't    

B. it won't      

C. tthere aren't    

D. there won't  

气设备引入装置金属挡板直径与进线装置内径之差不大于（）毫米，厚度不小于2毫米，金属垫圈外径与进线装置内径之差不大于2毫米，厚度不小于1毫米。

A、1

B、2

C、3

D、5

常用于根管机械预备的器械为（）

A.根管钻和冲洗器

B.根管钻和根管锉

C.金刚砂钻和根管锉

D.拔髓针和光滑髓针

E.扩孔钻和螺旋充填器

A local-area network (LAN) is a communications network that (125) a variety of devices and provides a (126) for information exchange among those devices. The scope of the LAN is small typically a single building or a cluster (丛) of buildings. The LAN is usually owned by the same organization that owns the (127) devices. The internal data rate of LAN is at least several Mb/s.
The basic of LAN communication is broadcasting. At each station, there is a transmitter/receiver that communicates over a (128) shared, By other stations. A transmission from any one station is (129) to and received by all other stations.

A．adopted

B．attached

C．selected

D．unified