TCP/IP （） layer protocols provide services to the application （） running on a computer. The application layer does not define the application itself, but rather it defines （） that applications need—like the ability to transfer a file in the case of HTTP. In short, the application layer provides an （） between software running on a computer and the network itself. The TCP/IP application layer includes a relatively large number of protocols, with HTTP being only one of those. The TCP/IP （） layer consists of two main protocol options—the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP).

In short, the application layer provides an （） between software running on a computer and the network itself.

A．iteration

B．object

C．interface

D．activity

液力传动的优点是（）

A.使发动机有良好的适应性

B.安全性能好

C.机械效率高，寿命长

D.调速和缓冲性能好

E.传动刚性好，效率高