Keep [one’s] nose to the grindstone

Keep [one’s] nose to the grindstone:

Definition:

 Hard working.

Example 1:

If you keep your nose to the grindstone, you will get a great reward.

If you are hard working, you will get a great reward. 

Example 2:

I got a raise because I kept my nose to the grindstone.

I got a raise because I was hard working.

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