The cam has a high point, or lobe; every time the cam rotates, the lobe comes around under the valve lifter and move it upward.是什么意思_The cam has a high point, or lobe; every time the cam rotates, the lobe comes around under the valve lifter and move it upward.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句