Free Steam Game Code - Daily Riddle #68 100% POWERUP-WEEK

welcome to the daily riddle #68!
We want to combine steemit.com and steam.com, so you can win one steam game everyday.
Solve the riddle and grab the random steam game code.

Rules:

The (x) are letters which must be solved in the following riddle
The (0) is a number betwen 0 and 9.
Vote and resteem that we can continue the riddles

My first is in airline but not in aerial
My second is in lawyer but not in layer
My third is in accommodation but not in contaminant
My fourth is in watermark but not in marketeer