完形填空。 
   Hi! I am a Chinese boy. I'm from Shanghai. 1 name is Li Qiang. I’m thirteen years old. I'm in Yucai Middle School in Shanghai. I 2 a round face, a big nose, a small mouth 3 eyes. Michael is a new student 4 our school. He 5 the U.S.A. He is tall and he 6short black hair. He 7 cool. He is thirteen years old, too. He and 8 are in the same school but in different 9. My English is not good, and he often10 me. We are good friends now.

小说按篇幅角度分：____ 、____ 、____ 、____。

质量M＝1kg的物体，在水平拉力F的作用下，沿粗糙水平面运动，经过位移4m时，拉力F停止作用，运动到位移是8m时物体停止，运动过程中E_K－S的图线如图所示。求：