Is "!DOCTYPE" case-sensitive?

The syntax for a class selector in css is

The ___ selector selects all HTML elements on the page.

Which of the following is not a newly added element in HTML5?

The CSS property border-spacing is given in what units?

In HTML ,tags that include both on and off tag are called

The _________ tag is required in all HTML documents and it defines the title of the page.

a property that allows developers to add rounded corners on the design elements ?

Which CSS property is used to define a delay before the animation starts?

What will happen if the height and width of a video are not set while the video loads?