protractor head造句

例句与造句

1. In the older design sets, the movement of the protractor head was assured by a pantograph system that could keep the head in the same springs.
2. The "'protractor head "'( two scales and protractor mechanism ) is able to move freely across the surface of the drawing board, sliding on two guides directly or indirectly anchored to the drawing board.
3. It's difficult to find protractor head in a sentence. 用protractor head造句挺难的