不是肺的非呼吸功能的是（）。

A.肺泡巨噬细胞灭菌功能

B.参与体内前列腺素的合成、储存、释放和灭活

C.参与酸碱平衡调节

D.肺具有过滤器功能

E.参与血管紧张素的活化

For each blank, choose the best answer from the four choices and write down on the answer sheet.

(66) is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.

(67) is a protocol that most USENET machines now use it to allow news articles to propagate from one machine to another over a reliable connection.

(68) is an approach preferred by cable TV providers. In this solution the fiber terminates at an optoelectrical converter and the final segment is a shared coaxial cable.

(69) is a device used to connect two separate network that use different communication protocol.

(70) is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.

67（）

A．RTP

B．RTTP

C．FTP

D．NNTP