尿Bence-Jones蛋白可见于（）

A.多发性骨髓瘤

B.巨球蛋白血症

C.原发性淀粉样变性

D.恶性淋巴瘤

E.肾盂肾炎

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

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

(2) 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.

(3) 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.

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

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

4（）

A．Router

B．Gateway

C．Bridge

D．Hub