关系模式中，表示实体间n：m联系是通过增加一个(36)。

(67)

(66)

(65)

(64)

(62)

IP multicasting is a set of technologies that enable efficient delivery of data to many locations on a network. Rather than making multiple copies of a message intended to be distributed to multiple recipients at the(71) of origin of a message, multicasting initially sends just one(72) and does not copy it to the individual recipients until it reaches the closest common point on the network, thereby(73) the bandwidth consumed. Network performance is significantly(74) because it isn't bogged down with the processing and transmission of several large data fries; each receiving computer doesn't have to(75) the transmitting server for the file.

(68)是用于多媒体及一些交互应用的传输协议，但对于大多数Internet应用，端到端的可靠有序传输是必须的，这些应用必须采用(69)协议。

(66)是为硬件配置较低的移动设备访问Web网络采用的协议，它与标准的(67)环境条件有很大的不同。

(60)

(58)