I feel stupid asking this. I have a new exmark metro 48. I looked in the owners manual on were I should grease it. They show different points. When I look on the mower to grease it are these holes, point were moving parts are????they mention zerks,,,, what is a zerk??? So to sum it up I am confused on were to put the grease. This is my first year on my own and I want to make sure I maintain my equipment. Thanks Mike