Many of the most flexible examples of tool use in animals come from primates(the order that includes humans, apes, and monkeys). For example, many wild primates use objects tothreaten outsiders. Or there are many examples of tool use by【S1】______the other mammals, as well as by birds and other types of animals.【S2】______ Tools are used by many species in the capture or preparation offood. Chimpanzees use sticks and poles to bring up ants and termites【S3】______(白蚁)from their hiding places. Among the most complex tool useobserving in the wild is the use of stones by Ivory Coast chimpanzees【S4】______to crack nuts open. They select a large flat stone as anvil(a heavy【S5】______block on which to place the nuts)and a smaller stone as a hammer.Stones suitable for use as anvils are not easy to find, but thus often a【S6】______chimpanzee may carry a haul of nuts more than 40 meters to find a suitable anvil. The use of tools in chimpanzees is especiallyinteresting while these animals sometimes modify tools to make them【S7】______better suited their intended purpose. To make a twig more effective【S8】______for digging out termites, for example, a chimp may first strip it of its leaves. Surprisingly, there is also a species of bird that use sticks to【S9】______probe holes in the search for insects. One of the species of Galapagos finch(雀类), the woodpecker finch, picks up or breaks off a twig, cactus spine, or leaf stem. This primitive tool is thenheld in their beak and used to probe for insects in holes in trees that【S10】______the bird cannot probe directly with its beak. Birds have been seen to carry twigs from tree to tree searching for prey.【S3】