“偶然地”的英语？

“偶然地”的拼音为：...

他们俩偶然地展开了一场斗智.The two of them had an encounter of wits.他几乎是偶然地找到了解决问题的办法.He hit upon the solution to the problem almost by accident.我是在坎特伯雷大教堂偶然地碰到过他.I met him by chance at Canterbury Cathedral....