起初我们着手研究的是看起来似乎最简单和最明显的滤波器.We started with what seemed the most simple and obvious filter.在适当条件下,多层膜还可作滤波器.Under appropriate conditions a multilayer may also be employed as a filter.这个信号送到滤波器 - 放大器,它是由变压器耦合到视频检波器的.The si...
The children were used as slave labour in gold mines in the jungle.在丛林地带，儿童被用作开采金矿的苦役。The report alleges that thousands of people have been forced into slave labour by the army.该报告宣称，成千上万的人被军队逼迫做苦役。He's been forced ...