User talk:74.109.216.106

Your recent edits
Hello, I'm 201.208.167.91. I wanted to let you know that one or more of your recent contributions to Center of mass have been undone because they did not appear constructive. If you would like to experiment, 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. 201.208.167.91 (talk) 05:18, 19 November 2017 (UTC)