在JavaScript中,下面代码表示获取到文本框的值,则下列选项中验证文本框为空的条件表达式不正确的是 ( ).(选择二项) var usrName = document.getElementById("txtName").value; A. usrName ==""; B. usrName.length=0; C. usrName=""; D. usrName.length<0 ;
【简答题】Once, the famous scientist Einstein travelled to many places in America to give lectures. He travelled in a __ 26 __ , and soon made friends with his driver. Each time Einstein gave the lecture, his d...