What are/is the most important difference between XHTML and HTML?

Which HTML attribute is used to set the space between the cell wall and the cell content in an HTML <TABLE> element?

An HTML image-map is an image with:

In a form, the INPUT tag can have many types. Which one is NOT a valid type?

In HTML 4.01, if OL stands for ordered list and UL stands for unordered list, what does the D in DL stand for?

Where should the <base> element be placed?

How many standard color names are defined in HTML 4.01?

Which of the following is not a valid input type in any version of HTML

Which of the following is NOT a valid <meta type="robots" content="<values>" /> value.

What does the <q> elements cite attribute do?

one attribute is used to identify an image as image map?