The digital voltmeter has to be powered with a power supply or batteries, while the magnetoelectric type meter only needs a battery in the ohms mode.是什么意思_The digital voltmeter has to be powered with a power supply or batteries, while the magnetoelectric type meter only needs a battery in the ohms mode.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句