The experimental telephone's ring is activated by pulses sent through a glass fiber . 这种实验性电话铃是依靠玻璃纤维所传送的脉冲激发而工作的。
2.
Low - level code handles the actual signals , such as the generation of electrical pulses sent over an ethernet cable or through a telephone modem 低阶程式码负责操纵真实讯号,比如产生电脉冲,并把讯号传送到乙太网路的缆线或电话数据机。