最早使用具有半圆形排线架的交换机和具有垂直和旋转运动方向的轴。

Earliest use of switch with semi-cylindrical bank and shaft with vertical and rotary motions.

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最早使用具有半圆形排线架的交换机和具有垂直和旋转运动方向的轴。

Earliest use of switch with semi-cylindrical bank and shaft with vertical and rotary motions.

youdao