电子转速表的英文：
electronic tachometer

electronic mailbox device for receiving and storing electronic mai
接受、储存电子邮递的装置.

Electronic mailbox device for receiving and storing electronic mail
接受、储存电子邮递的装置.

Do you have a marine electronic diploma?
你有航海电器执照吗？

stable electron orbit
稳定电子轨道

This is the lithium nucleus plus electron.
这是锂原子核加上一个电子。

"Welding carriage, screw-driven, powered by AC (VVVF) drive motor and controller with tachometer speed control. "
焊头小车,交流(VVVF)电机传动,有控制转速的控制器。