Imagine you are Alice, stepping through the looking glass. Suddenly everything is reversed. Doorknobs are on the wrong side of doors. The gearshift in your car is in the wrong place.Twenty-five million Americans wake up every day in just such an awkward situation. They are the one in ten of us who are left-handed and must face the world designed for the right-handed majority.Why we are left-or right-handed remains one of the great unsolved mysteries of science. We know that nearly two out of three lefties are male and that left-handedness runs in families. According to one study, almost half the offspring of two left-handed parents will be left-handed. The Scots-Irish family Kerr (from the Gaelic word for “left”) produced so many left-handers that in 1470 the family built its castle’s spiral stairways with a reverse twist to favor left-handed swordsmen.On the other hand, heredity (遗传) alone cannot explain lefties. At least 84 percent of them are born of two right-handed parents. And in 12 percent of genetically identical twins, one will be right-handed, the other left.Perhaps the greatest puzzle of all is not why some people are left-handed, but rather why so few are. So, scientists are trying to discover the truth of the matter, and they are beginning to gain insight into many ways left-handed differ from right-handed by considering how their brains work.(10.0分)(1) [单选题] How many of the Americans are left-handers?(2分) A、10% B、12% C、50% D、80%(2) [单选题]Among the left-handers ______.(2分) A、few are men B、most of them are women C、half of them are men D、 two thirds are men(3) [单选题]According to the passage, which of the following is NOT true?(2分) A、Almost half of the children of two left-handed parents will be left-handed. B、At least 84 percent of left-handers are born of two right-handed parents. C、One in ten of Americans are left-handed. D、In the majority of genetically identical twins, one will be right-handed, the other left.(4) [单选题]In the third paragraph, the word “offspring” means ______.(2分) A、 relatives B、sons C、daughters D、children(5) [单选题]The reason why so few are left-handed ______.(2分) A、has nothing to do with heredity B、 remains one of the great unsolved mysteries of science C、 has little to do with the working of their brains D、is that left-handers are mainly twins