Why do we cry? Can you imagine a life without tears? Not only do tears keep your eyes lubricated, they also contain a (36)______

Why do we cry? Can you imagine a life without tears? Not only do tears keep your eyes lubricated, they also contain a substance that kills certain bacteria so they can’t infect your eyes. Give up your tears, and you lose this on the spot defense. Nor would you want to give up the flood of extra tears you produce when you get something physical or chemical in your eyes. Tears are very good at washing this irritating stuff out. Another thing you couldn’t do without your tears is cry from joy, anger, or sadness. Humans are the only animals that produce tears in response to emotions. And most people say a good cry makes some feel better. Many scientists, therefore, believe that crying somehow helps us cope with the emotional situations. Tear researcher, William Fred is trying to figure out how it happens. "One possibility", he says, "is that tears discharge certain chemicals from your body". "When people talk about ’cry it out’ I think that might actually be ’what they are doing’", he says.
    If Fred is right, what do yon think would happen to people who restrain their tears? Boys, for example, cry only about a quarter as often as girls once they reach their teenage years. And we all cry a lot less now than we did as babies. Could it possible be that we face less stress? Maybe we found other ways to deal with it, or maybe we just feel embarrassed.