Tracer composition
[化] 曳迹剂
🧩 词语组成解析
tracer
['treisə]
n. 追踪者，描图者，（铁笔等）绘图工具;
🗣️ 情景例句
Which band of College English Test have you passed?
大学英语考试过了几级？
This telephone line is interrupted.
这个电话不通。
I rang the bell and was not surprised to see that Hugh was still as fat as ever.
我按响了门铃，当看到休仍和往常一样胖时，我并不感到惊奇。