材料一 我国某区域示意图

材料二 2017年4月1日，中共中央、国务院决定设立国家级新区雄安新区。这是中央深入推进京津冀协同发展作出的一项重大决策部署，对于集中疏解北京非首都功能，探索人口经济密集地区优化开发新模式，调整优化京津冀城市布局和空间结构，培育创新驱动发展新引擎，具有重大意义。

阅读理解

    Tom,Bill and Dave lost their backpacks．They are at the lost and found office．The backpacks are the same(相同的),but the things in them are different．Can you help them find the right(正确的)backpack?

    Tom：I have a  maths book and a pencil case in my backpack．There are three pencils,a pen and an eraser in the pencil case．

    Bill：I have a Chinese dictionary,a maths book and two notebooks in my backpack．

    Dave：There are two CDs,three picture books in my backpack．My English book is also in it．

一个人体检时站在磅秤上，秤的示数是50kg，这时人受到的重力大小是____ N，方向是____ ，这个力的施力物体是____ ．（g="10N/kg" ）