lubricate|lubricated|lubricates

记得定期给门铰链上油，这样开关会更顺畅。

Remember to ___lubricate the door hinges regularly for smoother operation.

在比赛前，他给自行车的齿轮上了油以减少摩擦。

Before the race, he ___lubricated the bike gears to reduce friction.

他定期给自行车链条上油以减少摩擦。

He regularly ___lubricates the bicycle chain to reduce friction.