//selected = $('#para-1');     //仅选择JavaScript
//selected = $('.color-red.color-green');  //仅选择Erlang
//selected = $('#para-1,.color-red.color-green')  //选择JavaScript和Erlang
//selected = $('[class^="color-"]');  //选择所有编程语言
//selected = $('input[name=name]');     //选择名字input
selected = $('input[name=name],input[name=email]');  //选择邮件和名字input