题目

Short stories for kids can provide them with a lot of fun and entertainment and also teach them the important values of life.There are some popular short stories around the world, For example, The Ugly Duckling, written by Hans Christian Anderson, which is based on the change of an ugly duckling into a beautiful swan, is one of the most inspiring short stories for children. Then there is The Boy Who Cried Wolf, a classic Aesop’s fable which shows kids the importance of always telling the truth. Little Red Riding Hood, which is written by the Brothers Grimm, tells kids about a strong and brav在图中，质量为20kg的物体在动摩擦因数为0.1的水平面上向右运动，在运动过程中受到水平向左、大小为10N的拉力作用，则物体所受摩擦力为(g取10N/kg) [　　] A．10N向右B．10N向左C．20N向右D．20N向左