signal

• Nancy signaled a waiter .
  南希朝侍者打了个手势。
• A second part is the transmission link-a radio signal .
  第二部分是传输线路--无线电信号。
• She smiled as she signaled cowperwood to follow her .
  她一边笑一边做手势叫柯柏乌跟她去。
• A tube or a transistor can amplify an incoming signal .
  电子管和晶体管能放大输入的信号。
• Bit sequences are digital signals varying with time .
  二进制序列是随时间变化的数字信号。
• He seems to be signaling .
  他似乎正在发送信号。
• The signal is at danger .
  （前面）有危险信号。
• Much as bats do, robots send out ultrasonic signals .
  机器人就象蝙蝠那样地发出超声波讯号。
• One may knock to signal one 's presence to others .
  可用敲击发出的声音向别人表示有人在此。