They spend suppertime summarizing the story they read in ninth-grade English that day, or explaining how Newton's laws of motion work.
他们用晚饭时间总结当天用九年级英语读到的故事,或解释牛顿运动定律的工作原理。
奇思妙想物语
Check out this example from their newest course — Scientific Thinking — you can change the size of the top ball, drag and drop the stack and visually learn about how motion works.
In horology, a wheel train (or just train) is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear trains which is not used in other applications of gears.