动物的行为按获得的途径可分为先天性行为和学习行为.根据以下两个材料回答:
材料一 草履虫不喜欢二氧化碳浓度高的环境,当草履虫在游动过程中偶尔靠近水中的一个二氧化碳气泡时,由于气泡酸性太强,它就停止游动,然后向后游,转动大约30度的角度后,再向前游,如果又游到距气泡太近的地方时,它便重复上述的移动次序,最后聚集在离气泡较远的微酸性区域.
材料二 成年的黑猩猩会利用经验来解决问题,当香蕉被挂到高处够不到时,黑猩猩就会把几个木箱堆叠起来,然后爬到木箱顶上去摘香蕉.
阅读短文,选择正确的答案。
Chen Jie and Chen Lin are sisters. Chen Jie is 14. She's 2 years younger than Chen Lin. But she's taller than Chen Lin. Chen Jie is 46 kilograms. She's l kilogram heavier than Chen Lin. Chen Jie likes sports. She plays sports every day. So she's stronger than Chen Lin. Chen Jie has short hair, but Chen Lin has long hair. They often wear the same size shoes. They wear size 36. They love each other.
____标志着中国人民从此站起来了。
(Ⅰ)求角A;
(Ⅱ)求函数y=2sin2B+cos C−2B2 的最大值.