以下哪一种CT征象最有助于脑外肿瘤的诊断（）。

A.边界不清

B.肿瘤沿脑镰或天幕生长

C.同侧脑室受压移位

D.病变与颅板交界呈钝角

E.血管源性水肿

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 HTTE 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).

A. application B. sessionC. physical D. transport