The most striking single fact about chimpanzees is flexibility of 【S1】______ their social life, the lack of any rigid form. of organization. It represents about so far a departure from the baboon type of organization as one 【S2】______ can find among the higher primates (灵长目), and serves emphasizing 【S3】______ the great variety of primate adaptations. Chimpanzees are more huma than baboons (狒狒), or rather they accord better by the way we like to 【S4】______ picture ourselves, as free—wheeling individuals who are tend to be 【S5】______ unpredictable, do not take readily to any form. of regimentation, and are frequently charming. Two researches have described what they found during more than eight months spending among chimpanzees in their 【S6】______ natural habitat, the forest: 'We were quite surprised to observe what 【S7】______ there is no single distinct social unit in chimpanzee society. Not only is there no 'family' organization; so is there a 'troop' 【S8】______ Organization—that is to say, no particular chimpanzees keep permanently together. On the contrary, individuals move about at will, alone or in small groups best described as bands, that sometimes form 【S9】______ into large aggregations. They leave their associates if they want to, and oin up with new ones with conflict. 【S10】______ 【S1】