Most people around the world are right-handed . This also seems to be true in history . In 1799 , scientists studied works of art made at different times from 1,500 B.C. to the 1950s . Most of the people shown in these works are right-handed , so the scientists guessed that right-handedness has always been common through history . Today , only about 10% to 15% of the world’s population is left-handed . Why are there more right-handed people than left-handed ones ? Scientists now know that a person’s two hands each have their own jobs . For most people , the left hand is used to find things or hold things . The right hand is used to work with things. This is because of the different work of the two sides of the brain . The right side of the brain , which makes a person’s hands and eyes work together , controls the left person’s hands and eyes work together , controls the left hand . The left-side of the brain , which controls the right hand , is the centre for thinking and doing problems . These findings show that more artists should be left-handed , and studies have found that left-handedness is twice as common among artists as among people in other jobs . No one really knows what makes a person become right-handed instead of left-handed . Scientists have found that almost 40% of the people become left-handed because their main brain is damaged when they are born . However , this doesn’t happen to everyone , so scientists guess there must be another reason why people become left-handed . One idea is that people usually get right-handed from their parents . If a person does not receive the gene（基因）for right-handedness , he / she may become either right-handed or left-handed according to the chance and the people they work or live with . Though right-handedness is more common than left-handedness , people no longer think left-handed people are strange or unusual . A long time ago , left-handed children were made to use their right hands like other children , but today they don’t have to . 小题1: After studying works of art made at different times in history , the scientists found . A. art began from 1, 500 B.C. B. the works of are ended in the 1950s C. most people shown in the works of art are right-handed D. most people shown in the works of art are left-handed 小题2:How many people in the world are left-handed now ?
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