What is the best Cross-Checking software?

My prof, a co-Author and I were working on a paper for more than a year. I was doing the math and simulations, my co-author was taking the care of writing and my professor was editing the paper. Now editing of the paper is done. Unfortunately, the co-author is not available now. My professor called me today and told me he has observed , my co-author copied some sentences from the reference papers. So He asked me to check all of the sentences and highlight and rewrite them again in the case I observed they are copied. He believes that, these days the reviewers are more concerned about the use of similar sentences in the paper. He said, they are more restrict about some countries (I belive it too, however some people might not be agreed).

So, What should I do? Check all sentences with other papers? This is not possible without using a machine.

Do you know what software I can use to do this? Please tell me any suggestion you have.

With regards.