题目

    It is quite apparent that competition surrounds every aspect of human life whether in the United States or the Amazon rainforest. Without it we would not have grown into primates (灵长类动物) . Or we would probably still be struggling to sharpen a bronze tool while crawling around on four legs in search of meat. Without competition, Columbus wouldn’t have discovered America and Edison would never have invented the light bulb. Friendship, like all relationships between two people, involves competition. It isn’t competition in a traditional sense because there are no goals有关生物膜系统结构和功能的叙述，正确的是（ 　）A．生物膜是对生物体内所有膜结构的统称B．变形虫和草履虫的细胞膜基本组成成分不同C．生物膜之间可通过具膜小泡的转移实现膜成分的更新D．不能体现生物膜系统在结构上的联系