JZJX type Roots-Vane vacuum system consists of the major pump i.e ZJ type Roots vacumm pump and the backing pump i.e. vane vacuum pump.是什么意思_JZJX type Roots-Vane vacuum system consists of the major pump i.e ZJ type Roots vacumm pump and the backing pump i.e. vane vacuum pump.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句