Once Farrant and her colleagues feel they have a better sense of which switches to throw, they will have to find the best way to do so in useful crops.
2018年6月六级真题（第一套）阅读 Section B
柯林斯高阶英汉双解学习词典释义
N-COUNT
(电路的)开关，闸，转换器
A switch is a small control for an electrical device which you use to turn the device on or off.
If you switch to something different, for example to a different system, task, or subject of conversation, you change to it from what you were doing or saying before.
If you switch your attention from one thing to another or if your attention switches, you stop paying attention to the first thing and start paying attention to the second.