What does 'don't judge a book by the cover' mean?

Besides the revisions listed in the paragraph, what else can deepak do to strengthen his paper?

From the life cycle of a plastic bottle, what is the best definition for the word “toxin”?

In this paragraph the author uses a real life example to demonstrate how do cryptography a. can the government. b. can be dangerous. c. is a swiss specialty d. is unreasonable expensive