青云翻译

The initial period of the quarterly change after oil clean six months to once a Year

Once every quarter for the early use, based on the cleanliness of oil for six months in the future ~ a year-for-a

Use initial period each Ji Huan one time, might later trade one time according to an oil clean situation half year ~ year

Use an initial for each season, a time after the clean oil will be in the first half to a year-for-one

Once every quarter for the early use, based on the cleanliness of oil for six months in the future ~ a year-for-a