[多项选择]桥面铺装层的功用有（）。
A. 增加梁主体的强度
B. 防止桥面板直接磨耗
C. 保护主梁免受雨水侵蚀
D. 分散车轮集中荷载
E. 使桥面的标高达到设计标高

{{B}}Cable Television{{/B}}
In the 1940s, there were four networks in the United States. Because of the frequencies allotted to television, the signals could only be received in a "line of sight" from the transmitting antenna. People living in remote areas couldn’t see the programs that were already becoming an important part of U. S. culture.
In 1948, people living in remote valleys in Pennsylvania solved their reception problems by putting antennas on hills and running cables to their houses. These days, the same technology once used by remote villages and select cities allows viewers all over the country to access a wide variety of programs and channels that meet their individual needs and desires. By the early 1990s, cable television had reached nearly half the homes in the United States.
Today, U. S. cable systems deliver hundreds of channels to some 60 million homes, while also provid
A. a "line of sight"
B. transmitting antenna
C. frequencies allotted to television
D. putting antennas on hills and running cables to houses