根据短文内容，在空格内填入合适的单词或写出括号内所给单词的适当形式。（每空一词）
Dear Liz,
Thank you very much ____ your letter and the photos of your ____(friend) and family. Your parents and friends look really nice ____ the photo. Now I can tell you something about me and ____ family here in New York.
I've got two brothers. ____(they) names are Lukas and Andreas and they ____(be) 16 and 19. My mother is French and her name is Christine. Dad is American and his name's Dieter. Our house ____(have) got four bedrooms and a small garden. My room is tidy, but my ____(brother) is not. They don't often clean it. We have a dog, Zak, and we think he's cute. We ____(love) it a lot.
Please tell me all about ____ friends and school in your next letter. I'd like to know about English schools.
Love,
Laura
，y为该点到地面的距离，c为常数，B0为一定值．铝框平面与磁场垂直，直径ab水平，(空气阻力不计)铝框由静止释放下落的过程中( )