The specify letters combinations I think none of them is challenging.My judgement in kerning change in revolution is I went along with other group of words I see that my kerning got better.The first attempt on kerning on first sentence is easy to read the letters wasn’t close to each other.I change in the second attempt with thinking about giving more space betweeen the lines which I did.Im glad I did good tracking in the second attempt because that gives good connection between the sentences.