关于辐射防护原则哪项是错误的（）。

A.尽可能减少放射性物质进入人体

B.尽量不进行放射性检查

C.减少接触放射源时间

D.增大与放射源的距离

E.设置防护屏蔽

(71) is a one -way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.
(72) 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.
(73) 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.
(74) is a device used to connect two separate network that use different communication protocol.
(75) is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.

A．NNI

B．NRZ

C．NAK

D．NVT