Read the passage and answer the following question:
(1) The brain is where we do our thinking. (2) All our senses are tied into our brain allowing us to experience the outside world. (3) We remember, have emotions, solve problems, worry about stuff, dream about the future, and control our bodies in our brain.
(4) For such an awesome organ, the brain doesn't look like much. (5) It's a ball of gray looking wrinkled tissue about the size of two of your fists put together. (6) The brain sits in our hard, thick skull with membranes and fluid around it to protect it.
(7) The brain is part of the nervous system. (8) Together with the spinal cord, it makes up the central nervous system. (9) The brain connects to nerves that travel throughout the body. (10) Nerves from our senses (hearing, seeing, touch, etc.) send signals to the brain to let the brain know what is going on in the outside world. (11) The brain also sends signals using nerves to muscles in order to make our body move.
(12) It has short term memory and long term memory. (13) Scientists are still learning exactly how memory works, but they know that short term memory allows us to remember something for a very short time without rehearsing or practicing it. (14) We can't remember a lot of things in short term memory though, and, like its name suggests, these memories don't last very long.
(15) The brain may not move but it needs lots of energy. (16) Energy is sent to the brain by our blood. (17) There are lots of blood vessels and blood flowing through the brain at all times. (18) The brain actually uses around twenty percent of the body's energy.
(19) The brain is divided into two halves. (20) Since the nerves cross when they enter the brain, the left side of our brain controls the right half of our body and the right side controls the left. (21) Each half also controls specialized functions. (22) What each half does depends on whether you are left or right handed. (23) In a right-handed person, the left side of the brain is used for language and numbers while the right side is the more artistic side and is also used for recognizing objects.
Which of the following would be the best topic sentence to come before sentence 12?
What is the best way to fix sentence 15, reproduced here:
"The brain may not move but it needs lots of energy."
Which sentence should be removed from paragraph 6 to improve the focus?
What is the best way to write sentence 19, reproduced here:
(19) "The brain is divided into two halves."
What is the correct way to write the underlined portion of sentence 7, reproduced here:
For such an awesome organ the brain doesn't look like much.