vacuum tube curve tracer

例句：

1. 1.The vacuum tube was used as a source of light in the early days of electronics.
   在电子学的早期阶段，真空管被用作光源。
2. 2. The electron microscope is a tool that allows scientists to observe the structure of matter at a very small scale.
   电子显微镜是一种工具，科学家可以使用它来观察物质在非常小尺度上的结构。
3. 3.The curve tracer was used to map out the path of the electron beam during the experiment.
   曲线示踪剂被用来在实验中绘制出电子束的路径。