fur is a covering around the body of an animal & a covering can be used as protection against cold weather ->  thick fur can be used for keeping warm  thick fur can be used for keeping warm & an animal requires warmth for survival in a cold environment ->  thick fur can be used for survival in a cold environment by keeping warm  snow is cold & snowy means a large amount of snow ->  a snowy environment is a cold environment  thick fur can be used for survival in a cold environment by keeping warm & a snowy environment is a cold environment ->  thick fur can be used for survival in a snowy environment by keeping warm  thick fur can be used for survival in a snowy environment by keeping warm & something that is used for survival has a positive impact on survival -> thick fur has a positive impact on an animal's survival in a snowy environment