A disc brake on oil drilling rig is a composite braking system composed of normal open braking calipers and normal closed braking calipers.是什么意思_A disc brake on oil drilling rig is a composite braking system composed of normal open braking calipers and normal closed braking calipers.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句