常見例句雙語例句There are different kinds of valves ranging from simple hand operated valve to fully automatic valve for control of gas-air mixture.有很多從簡單的手閥等各種閥到全自動控制天然氣混空氣閥。www.tech-domain.comThe opening and the closing of the gate valve are realized by a manual pump; the past bulky gate valve with a hand-operated screw rod is replaced.閘閥的開啟和關(guān)閉靠手動泵來實現(xiàn)，取代了過去手搖絲杠的笨重閘閥。ip.com 返回 hand-operated valve