TCP/IP (71) layer protocols provide services to the application (72) running on a computer. The application layer does not define the application itself, but rather it defines (73) that applications need--like the ability to transfer a file in the case of HTTP. In short, the application layer provides an (74) 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 (75) layer consists of two main protocol options--the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP).

（75）处填（）。

A．application

B．session

C．physical

D．transport

“查找与替换”对话框的快捷键是（ ）

A．Ctrl+H

B．Ctrl+Alt+F

C．Ctrl+F

D．Ctrl+Alt+H