如图所示，一质量为m的小球套在一“”滑杆上，小球与滑杆的动摩擦因数为μ=0.5，BC段为半径为R的半圆，静止于A处的小球在大小为F=mg，方向与水平面成37°角的拉力F作用下沿杆运动，到达B点时立刻撤去F，小球沿圆弧向上冲并越过C点后落在D点（图中未画出），已知D点到B点的距离为R，且AB的距离为s=10R （sin37°=0.60，cos37°=0.80）试求：

18世纪的法国，越来越多的人不再盲从统治者的说教，学会用自己的头脑思考问题。他们思考的问题与文艺复兴、宗教改革时期相比，突出表现在

任务型阅读根据短文内容，判断正误。
    When I grow up，I'm going to do what l want to do．I'm going to move somewhere interesting．Paris (巴黎)sounds like a city that I could enjoy．There are lots of art exhibitions(艺术展)．I want to be an artist．So how am I going to do it? First，I'm going to find a part-time job for a year or two and save some money．And I'm going to be a student at an art school in Paris．And l want to learn French at the same time．Next，I'm going to hold(举办)art exhibitions because l want to earn some money(挣一些钱)and buy a big house for my parents．I also want to travel all over the world．One day I'm going to retire(退休)somewhere quiet and beautiful．

We have to go shopping____(two) a week, on Saturday and Sunday.

（2017•鄂州）甲、乙、丙三种固体物质的溶解度曲线如图所示，回答下列问题：