.animate( properties, options )这里的options是什么意思?有什么作用?能举个例子吗?
$('#elem').animate({ width: 'toggle', height: 'toggle' }, {
duration: 5000,
specialEasing: { width: 'linear', height: 'easeOutBounce' },
complete: function() { $(this).after('Animation complete.'); }
});