I need help on these sentences.

Are these sentences correctly punctuated.

A crisp, juicy apple a day keeps the doctor away.

She is wearing a new yellow dress, and looks clean and neat.

The sheikdom of Bahrain has a settled well-educated population.

The major economic powers include the United States Japan and Germany.

Any help would be appreciated I have been working on this for over an hour and I am coming up with 1 or 2. 3 does not make sence to me. I know that 4 is not correctly punctuated. Thanks
Add commas after 'settled' and 'States' and you'll have it. (Some folks may want a comma after 'new', but I don't.)
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then it would also not be 2 because would you not have to put a comma after clean, and neat. Thanks .
No, the comma is precluded by the 'and' of clean and neat.
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