Because the @-Webkit-Keyframes Rule and the :Valid Pseudo-Class Are Not

question 13

Short Answer

Because the @-webkit-keyframes rule and the :valid pseudo-class are not part of the CSS specification, they cause __________ errors.

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Definitions:

Tennis Balls

Small, usually yellow, hollow rubber balls covered in a fibrous felt, used in the game of tennis.

Tennis Racquets

Sporting equipment consisting of a handled frame with an open hoop across which a network of strings is stretched, used to hit a tennis ball.

Demand Schedule

A table that shows the quantity of a good or service that consumers are willing to buy at each price point.

Supply Schedule

A table that shows the relationship between the price of a good and the quantity of that good a supplier is willing to offer for sale at each price level.