沥青路面的施工厚度检测的方法有哪些？

预应力混凝土结构的优点是（）。

A.同力截面小

B.工艺简单

C.同跨度重量轻

D.不需养护

E.抗裂强

以下关于金瓷冠的描述，错误的是（）

A.瓷层越厚越好

B.镍铬合金基底冠较金合金强度好

C.避免多次烧结

D.体瓷要在真空中烧结

E.上釉在空气中完成

●ICMP 协议属于TCP/IP 网络中的（）协议，ICMP 报文封装在（）协议数据单元中传送。

ICMP 报文封装在（）协议数据单元中传送

A．IP

B．TCP

C．UDP

D．PPP

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

A．MD

B．RSA

C．DES

D．MIB

腰阳关位于第5腰椎棘突下。