题目：

Add the following 5 steps to the animation "example" (using 0%, 25%, 50%, 75%, and 100%):

1. 0% - Set background color to "red", left position to "0px", top position to: "0px"
2. 25% - Set background color to "blue", left position to "0px", top position to: "200px"
3. 50% - Set background color to "green", left position to "200px", top position to: "200px"
4. 75% - Set background color to "yellow", left position to "200px", top position to: "0px"
5. 100% - Set background color to "red", left position to "0px", top position to: "0px"

提示：The % values represents the different stages of the animation. 0% is the start, and 100% is the end.