资料题：Scientists used to think we inherited this tendency（　）。

Which of your two hands do you use most? Very few of us can use both of our hands equallywell.Most of us are right-handed.New-born babies 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 thishappens.They used to think that we inherited this tendency from our animal ancestors, but this may not be true.Monkeys are our closest relatives in the animal world.Scientists have found thatmonkeys 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 200, watch the monkeys carefully.You'll see that some of them will prefer to swing from theirright 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.We live in a night-handed world.