How to translate these sentences to chinese? thx.

1,
It certainly goes a long way to explaining why we spend so much money on beauty products and pampering ourselves.
go a long way to doing ------?

2,
As winter begins to set in after a magnificent summer, SAD syndrome is likely to rear its ugly head for many of us.

3,
Walking is promoted by all health enthusiasts and is a great way of exercising as well as building confidence and improving self-esteem or even letting off steam.
let off steam------?