语法填空。
I'm Lucy．This is a map of our school．____six buildings(楼房)in it．They are a dining hall，an art building，a sports hall，a science building，a classroom building and a library．Our classroom building is ____the science building．And it's ____ the library．In the middle of our school,____a big playground(操场)．We often play sports on it．Next to the playground is the art building．It's____the dining hall and the sports hall．Our school is big，and it's nice．
处的切线方程是
的速度水平抛出一物体，忽略空气阻力的影响，当其水平分位移与竖直分位移相等时，下列说法正确的是（ ）
