Looking on the internet deeply has found these results:

earn a mark in is the most popular phrase on the web.

earn a mark at 13 results on the web	earn a mark in 16 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
He must pass the final test Before he earns the mark of. He must pass the final test Before he earns the mark of batiatus. See this act to successful completion, and earn the mark of the brotherhood. See this act to successful completion, and earn the mark of the brotherhood. And she earns every mark she gets. The man will earn the mark, and see investment well returned. You still have to earn your 10 Marks, dude! Until late into Sunday, it looked like Nice too might earn such a mark.	The man will earn the mark, and see investment well returned. He must pass the final test Before he earns the mark of batiatus. Until late into Sunday, it looked like Nice too might earn such a mark. See this act to successful completion, and earn the mark of the brotherhood. You still have to earn your 10 Marks, dude! See this act to successful completion, and earn the mark of the brotherhood. He must pass the final test Before he earns the mark of. And she earns every mark she gets.

earn a mark at

13 results on the web

earn a mark in

16 results on the web

More popular!

He must pass the final test Before he earns the mark of.
He must pass the final test Before he earns the mark of batiatus.
See this act to successful completion, and earn the mark of the brotherhood.
See this act to successful completion, and earn the mark of the brotherhood.
And she earns every mark she gets.
The man will earn the mark, and see investment well returned.
You still have to earn your 10 Marks, dude!
Until late into Sunday, it looked like Nice too might earn such a mark.

The man will earn the mark, and see investment well returned.
He must pass the final test Before he earns the mark of batiatus.
Until late into Sunday, it looked like Nice too might earn such a mark.
See this act to successful completion, and earn the mark of the brotherhood.
You still have to earn your 10 Marks, dude!
See this act to successful completion, and earn the mark of the brotherhood.
He must pass the final test Before he earns the mark of.
And she earns every mark she gets.