User talk:67.230.79.69

December 2021
Hello, I'm Nick Levine. An edit that you recently made to Mass–energy equivalence seemed to be a test and has been reverted. If you want to practice editing, please use the sandbox. If you think a mistake was made, or if you have any questions, you can leave me a message on my talk page. Thanks! Nick Levine (talk) 15:23, 29 December 2021 (UTC)