贊！做的很好，繼續努力，加油！把代碼快照下，分析下是什么情況。

報錯了 ?你的很多分號寫的是中文輸入法的

function?bind(el,eventType,callback){
????if(typeof?el.addEventListener?===?'function'){
????????//這行多寫一個?el
????????el.addEventListener(eventType,callback,?false);
????}else?if(typeof?el.attechEvent?===?'function'){
????????el.attachEvent('on'?+?eventType,?callback);
????}
}
function?mouseoverHandler(e){
????var?target?=?e.target?||?e.srcElement;
????var?outer?=?document.getElementById('subject');
????//這行的;是中文的
????var?list?=?outer.getElementsByTagName('li');

????for(var?i?=?0;?i?<?list.length;?i++){
????????list[i].className?=?'';
????}
????while(target.tagName?!=?'LI'?||?target.tagName?==?'BODY'){
????????target?=?target.parentNode;
????}

????target.className?=?'big';
}

function?initList(){
????var?outer?=?document.getElementById('subject');
????//這行的;是中文的
????var?list?=?outer.getElementsByTagName('li');
????for(var?i?=0;i?<?list.length;?i++){
????????bind(list[i],'mouseover',?mouseoverHandler);
????}
}

initList();

看注釋，一共3個錯誤