Gear tooth face serious wear new gear should be changed, if only gear at both ends of the plane wear, can be in surface grinding machine on grinding repairlight.
齿轮齿面严重磨损时应更换新齿轮，如果只是齿轮的两端平面磨损，可在平面磨床上磨削修光。
2
Your body needs to experience all three steps of sleep—light sleep, dream, and deep sleep—to fully repair itself.
你的身体需要经历睡眠的三个步骤——浅睡眠、做梦和深睡眠——从而进行完全的自我修复。
3
They received a shot of genes near their retinal cells to repair their light receptors.