我在谷歌浏览器上测试 32.0.1700.76 m

选择标签中的最后一个选项没有从鼠标获得悬停效果.

通过键盘使用时高亮显示.

这是Bug.问题 336348:鼠标悬停时未突出显示选择的最后一个选项

另请参阅 问题 334227:[Aura] Regression : Last dropdown item鼠标悬停时未突出显示

这不是您的代码问题，而是由于 Google Chrome 错误.

如果有超过 3 个选项，这个错误就会发挥作用.

此问题已在 Google Chrome 最新版本 32.0.1700.102 m 中得到修复.

解决方案将您的谷歌浏览器更新到最新版本.

I am testing it on Google Chrome 32.0.1700.76 m

The last option in the select tag is not getting the hover effect from mouse.

It is highlighting when using through keyboard.

It is Bug . Issue 336348:Last option of select does not get highlighted on mouse hover

and also see Issue 334227:[Aura] Regression : Last dropdown item not highlighted on mouse-hover

It's not the problem with your code it's due to Google Chrome Bug.

With more than 3 options this bug comes into play.

This issue has been fixed in Google Chrome latest Version 32.0.1700.102 m.

Solution Update your Google Chrome to latest Version.