Which is correct use of border-radius?

In CSS3 it is possible to specify the size of the background image...

What line of HTML would you use to reference an external style sheet?

If a layout is created in a PSD with blue buttons in the nav, then it would be best for the speed of the page to:

When style in different locations conflict, which will take precedence?

In webkit, in order to set the transition duration you must first:

Which of these is not a valid CSS3 color value?

What does this selector do? ul ~ p { color: red; }

All properties must have a:

What is the earliest version of Internet Explorer that supports border-radius?

In HTML5, how can you visually center this <div class="center">hi</div>?