Look at the picture. What can you see? In the picture there is a big table with a lot of things on it. There are three bottles of orange juice, two glasses of milk, some bread, cakes and so on. look, there is a cat under the table. It’s Kate's cat. Its name is Mimi. I think it like them very much. No, Mimi. You can't have them. All the things on the table are not for you. They are for Jim and Kate. They have them for lunch. POLLY is a bird.  Now it's on the window. It’s eating a banana.

如图所示，在离地高h处以初速v_o抛出一个质量为m的物体，不计空气阻力，取抛出位置为零势能位置，则物体着地时的机械能为（　　）

如图，直线AB与直线CD相交于点O，OE⊥AB，垂足为O，∠EOD=$\frac{1}{2}$∠AOC，则∠BOC=（   ）

千骑卷平冈