common machines

• 常用机械

common machines的用法和样例：

例句

1. In the past, the state lotteries have used mechanical drawing machines, such as the spinning drums with numbered ping-pong balls inside, to select the random numbers.
   过去，州的彩票用机械摇奖机，就是标上数字的兵乓球在圆形容器中运动，选出号码。