Which of your two hands do you use much better? Very few of us can use both of our hands equally well. Most of us are right - handed. Only about five people out of a hundred are left - handed. Newborn ha bies can grasp objects with either of their hands, but in about two years they usually prefer to use their right hands. Scientists don't know why this happens. They used to think that we inherited (继承) this tendency from our animal ancestors (祖先), but this may not be true. Monkeys are our closest relatives in the animal world. Scientists have found that monkeys prefer to use one of their hands more than the other, but it can be either hand. There are as many right - handed monkeys as there are left - handed ones. Next time you visit the zoo, watch the monkeys carefully. You' 11 see that some of them will prefer to swing from their right hands, and others will use their left hands. But most human beings use their right hands better, and this makes life difficult for those who prefer to use their left hands. Most of us use our right hands ______ the left ones.