How do I add AdBlock Plus to Firefox?

Related questions

1. Does AdBlock slow down browsing?
2. Where do I find ad blocker?
3. What is the difference between Mozilla and Firefox?
4. How do I get rid of ads on Firefox?
5. What is uBlock origin Firefox?
6. Why do I still get pop ups when I have them blocked?
7. Does Firefox have an ad blocker?
8. Does Firefox have a built in AdBlock?
9. What is the difference between Chrome and Firefox?
10. Is Firefox Chrome based?

Tags

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2. #screen
3. #firefox
4. #first
5. #please
6. #button
7. #mozilla
8. #green
9. #adblock
10. #click
11. #authors
12. #section
13. #following
14. #opened
15. #trust
16. #install