Shuttling
n. 往复运动；梭动
🗣️ 情景例句
How long will this be on sale?
这种商品减价时间有多久？
The weather is promising.
天气可能好转。
When the instrument is situated at more than 700 miles from the earthquake centre,
如果把这种仪器安装在距震源700多英里远的地方，