He is tarnishing his reputation by being a shill for the tobacco industry.

他因为烟草工业做托儿而在玷污他的名誉。

Patted him of dust, for fear of tarnishing the sanctity of the place.

拍拍身上的尘埃，生怕玷污了这圣洁的地方。

Bright tin electrodeposits on copper wire are susceptible to tarnishing.

铜线材经光亮镀锡后易产生腐蚀变色。

Silver dials are then rhodium or even fine silver to prevent tarnishing.

银色表盘铑甚至是精细的银，以防止变色。

You can use chemistry to reverse the tarnishing reaction, and make the silver shiny again!

你可以同样用化学方法来逆反这种“暗淡反应”，让银器们变回亮丽！