Derestimating the intelligence of the american public

Question

A. Correct the errors in the following sentences_:

1. The man who views the world at fifty the same as he did at twenty," remarked the boxer Muhammad Ali, has wasted thirty years of his life
2. _{Do you agree with Jerry Seinfeld that: "A bookstore is one of the only pieces of evidence we have that people are still thinking?"}
3. _{H. L. Mencken cynically remarked that, "Nobody ever went broke un- derestimating the intelligence of the American public.}
4. _{It has been my experience, said Abraham Lincoln that "folks who have no vices have very few virtues.}
5. _{The American historian Barbara Tuchman wrote about the ineptitude of generals, arguing that: "The power to command frequently causes failure to think".}