Sparkproof
a. 不发出闪光的,不发出火花的
🗣️ 情景例句
Philip works late. Philip
工作到很晚。
When are visiting hours over?
探病的时间到几点为止呢？
It was from the study of these that so much was learnt about the interior of the earth.
正是从这两种波的研究中，我们可以了解到地球内部的许多情况。