The experimental telephone's ring is activated by pulses sent through a glass fiber.

这种实验性电话铃是依靠玻璃纤维所传送的脉冲激发而工作的。

youdao

The experimental telephone's ring is activated by pulses sent through a glass fiber.

这种实验性电话铃是依靠玻璃纤维所传送的脉冲激发而工作的。

youdao