User:Penglangchen

March 2011
Welcome to Wikipedia. Although everyone is welcome to contribute to Wikipedia, at least one of your recent edits, such as the one you made to Division by zero, did not appear to be constructive and has been reverted or removed. Please use the sandbox for any test edits you would like to make, and read the welcome page to learn more about contributing constructively to this encyclopedia. Thank you. Dmcq (talk) 15:22, 3 March 2011 (UTC)