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).

（73）处应填（）。

A．services

B．processes

C．applications

D．address

有关支气管哮喘发病机制不正确的是（）

A.气道慢性炎症是哮喘的本质

B.气道高反应性（AHR）者均可诊断哮喘

C.变应原进入体内后可诱发机体释放多种活性介质诱导哮喘发生

D.迟发型哮喘反应（LAR）是由于气道慢性炎症的结果

E.神经因素也认为是哮喘发病的重要环节