Table CSS issue

Hi,

I encountered a problem on one of my pages here: http://www.dailyenglishtests.com/simple-present-2/ (if it asks for a username and passwords, they are: daily, daily)

If you scroll down, you'll see three buttons side by side. They are in a table. When you hover over, the background will be highlighted in blue. It's probably some kind of conflict between the theme and the plugin. How can I remove that highlight? And also how can I remove the borders around the buttons?

Thanks

It appears that the display of those buttons is controlled by the selectors:

Code:

---

<table class="watupro_buttons" id="watuPROButtons1">

---

The theme uses many style sheets but there is one called 'buttons.css?ver=7.8'. I would start there.