Question

IM MARKING BRAINLIEST TO THE CORRECT ANSWER

Answer 1

I would say sentence #4 should be revised, because if you read it aloud it doesn't sound natural. Some revision to the sentence would make it flow smoother than it already does. The part that would need to be revised would be " Almost all water naturally contains some level of fluoride" Instead the author should put a percentage or number.

Answer 2

I am 99.9% sure it is 4