1. "He returned to Europe 2010."<br/><br/>2. "He returned to Europe in 2010."<br/><br/>3. "He returned to Europe March 2010."<br/><br/>4. "He returned to Europe March, 2010."<br/><br/>5. "He returned to Europe March of 2010."<br/><br/>6. "He returned to Europe March in 2010."<br/><br/>7. "He returned to Europe in March 2010."<br/><br/>8. "He returned to Europe in March in 2010."<br/><br/>9. "He returned to Europe in March of 2010."<br/><br/>10. "He returned to Europe in March, 2010."<br/><br/>Which ones are not acceptable standard English?