When Bill is very young, he loves picture. His mother often draws some for him on old pieces of paper. She is very bad at drawing, but bill likes her pictures and always wants more. Then, when he is a little older, Bill’s mother gives him some pencils and a drawing book, and he begins drawing pictures, too. But they are never good .When Bill is five years old, his mother gives him a small blackboard and some pieces of a baby on the blackboard, he draws lines(线条) and rubs(擦) them out too for ten minutes , but when he looks at his picture , he is not happy. “Well”, he says at last(最后) to his mother, “I’ll put a tail(尾巴) on it and make it a monkey.”

2016年10月17日，___________载人飞船发射升空后准确进入预定轨道，11月18日，返回舱顺利着陆。（    ）

若x，y为实数，且|x+2|+$\sqrt{y-2}$=0，则($\frac{x}{y}$)²⁰¹³的值为（　　）

下列哪项不是所有鸟类的生殖和发育都必须经历的：（　　）