var listen = function(value){console.log("99999upup");var liArray=document.querySelectorAll("div[class^='answerProblem'] ul li");if(!!liArray && liArray.length>0){var answer = !!value ? value : findAnswer();if("A"==answer){liArray[0].click();}else if("B"==answer){liArray[1].click();}else if("C"==answer){liArray[2].click();}}};var findAnswer = function(){var content = document.getElementsByClassName('Barrage-main')[0].innerText.toUpperCase();var re = /[^ABC]/g;var answerContent = content.replace(re, '');var json = {};for (var i = 0, l = answerContent.length; i < l; i++) {json[answerContent[i]] = (json[answerContent[i]] + 1) || 1;}var tempVal = 1, tempKey = answerContent[0];for(var key in json){if(json[key] > tempVal){tempKey = key;tempVal = json[key];}}console.log('answer:' + tempKey);return tempKey;}var start = function(value){console.log('输入stop();按回车后停止'); t = setInterval(listen, 50, value);}var stop = function(){clearInterval(t);}