求翻译：　　刹车片和刹车碟(鼓)是有使用寿命的，当它们磨损到一定程度时必须更换。一般城市行车中的正常使用，它们的寿命大约是5万公里，刹车片的寿命在3万公里左右，但是具体情况还要看车主的操作情况，最好是每1万公里检查一次。　　是什么意思？

Brake pads and brake discs (drums) is a life, to a certain extent when they wear must be replaced. General urban traffic in normal use, their lifespan is about 50,000 km, the life of brake pads at 30,000 km, but the owner of the operation depends on the specific circumstances of the case, it is best

Brake drums and brake disc is a lifetime of wear, and when they need to be replaced when they reach a certain degree. general urban traffic in normal use of their life expectancy is approximately 50,000 km, brake life expectancy of 30,000 km around in specific circumstances, but we must also look at

　　The brake lining and the brakes small dish (drum) has the service life, when they wear down to certain degree must replace.In the general city driving normal use, their life probably is 50,000 kilometers, the brake lining life about 30,000 kilometers, but the special details also need to look vehi

　　Brake pads and brake (drum) is a life, to a certain extent must be replaced when they wear.　　Normal use in the General urban traffic, their life expectancy is about 50,000 km, brake pad life at 30,000 km or so, but the case also depends on the owner's actions, preferably once every 10,000 km check

　　Brake pads and brake (drum) is a life, to a certain extent must be replaced when they wear.　　General normal use in urban road, them life is about 50,000 km, brake pad life at about 30,000 km, but specific circumstances depends on owners of operation, preferably every once in 10,000 km.