Common mistakes that writers make include ones relating to

i guess the cause and effect would show how being around the smoke(the cause) can have negative effects on the body.

explanation:

mark twain, real name samuel langhorne clemens, was an american writer, humorist, entrepreneur, publisher, and lecturer. among his novels are the adventures of tom sawyer and its sequel, the adventures of huckleberry finn, the latter often called "the great american novel". wikipedia

black citizens were denied access to the same public facilities as whitesun.

marriages between white and nonwhite citizens were forbidden.

nonwhite citizens were required to carry identification papers with them at all times.

laughter improves people's emotional and well-being.   kavita khajuria is a psychiatrist and he has defined laughter as " physical expression of humour and joy that has numorous protective qualities." when you feel under stress or sad because you have argued with a person you love, you need to laugh to feel strong enough to face the problems.

when you have an exam , you probably feel under stress. laughing will you release this tension. humour decreases the hormones that cause stress. k. khajuria   says that the brain releases some chemical components when we laugh. these chemical components are called neurotrophic factors and they are very important. they support the neurons in the brain and encourage the growth of new neurons. as a conclusion, you should laugh a lot before giving your exam. laughing will you with your exam and with your brain.

if you are having difficult times with friends or family members, laughing will also you face these problems. alannagh kelly is an assistant psychologist. she thinks that laughter can   make anger and anxiety vanish in the air. laughter can set a new and exciting atmosphere among people and it can make the bonds bewteen people stronger. so, if you are having a difficult time with someone you love, invite him / her to watch a comedy. you will probably make peace.

laugher will certainly protect you against stress and emotional pain. watching a comedy   may be a solution to stress or damaged bonds. " this remedy is fun , free, and best of all, no instructions needed."   alannagh kelly has said in her blog.