1.expert (n.)专家；行家；能手
As an expert in English, what would you advise me to prepare for the contest?
作为一个英语专家，您建议我为比赛准备些什么呢？
2.machine (n.)机械，机器
Do you know how to handle the machine?
你知道这机器应怎样操作吗？
3.turn off 关掉一些东西
Suddenly you discover something wrong with the faucets. You canvt turn off the water!
突然你发觉水龙头不对劲，怎么关也关不上!
4.be used in 用于
Copy this string so it can be used in the next step
复制这个字符串，以便在下一步中使用。