Skill you are
practising: Certain, probable, unlikely and impossible
We strongly suggest that you do not refresh this page as it resets your progress. Questions will be shown
automatically. Your target is to achieve 10 stars to earn the certificate of mastery for this skill.
You did it! You've successfully mastered a skill.
You did it! You've successfully mastered . The awards and
certificate have been added to your account. Well done and keep it up!