The least significant heading tag among HTML heading tags is _____.

Every HTML element may have an itemscope attribute specified.

The tag is a fallback tag for browsers that do not support frames.

The __________ CSS pseudo-class represents elements that do not match a list of selectors.

The _________ tag defines an explanation or pronunciation of characters (for East Asian typography) in a ruby annotation.

Align the following text towards the center.

<p class="align">This line of text</p>

The ::backdrop CSS pseudo-element is a box the size of the viewport which is rendered immediately beneath any element being presented in full-screen mode.

The -webkit-box-flex CSS properties specify how a -webkit-box grows to fill the box that contains it, in the direction of the containing box's layout.

The border-end-end-radius CSS property defines a logical border radius on an element, which maps to a physical border radius that depends on the element's writing-mode, direction, and text-orientation.

Which of the following statements is true about the background-color property in CSS?