长方孔 meaning in Chinese
slot
Examples
- Slots with round end and slots with square end plate screens
长圆孔和长方孔筛板 - Slot mesh screen
长方孔筛 - 4 . make a rectangular hole on any side of the box to observe the projection of the sun . the hole should be big enough to see the whole screen
四在盒子其中一个侧面，开一个长方孔，作观测太阳投影之用，开口不用太大，以清楚看见底部屏幕为合。