题目

根据材料内容理解，选择正确答案。 In America, there are chores(杂活) for children of different ages. American people think that it's important to tell children their duty in the family.Ages 4-6Ages 6-12Ages 13 and Up-Make their bed;-Clear dishes from the table;-Set the table;-Get the mail from the mailbox;-Take care of pets;-Cook simple food;-Help wash the car;-Vacuum(吸尘) and sweep;-Take out the rubbish.-Wash windows;-Clean out fridge;-Prepare a meal;-Make shopping lists;-Mow the lawn(剪草坪) （1） This passage discusses something about _______. A . American c10．如图所示，实线为某电场的电场线，虚线为某一带负电粒子只在电场力作用下的运动轨迹，M、N为运动轨迹上两点，下列说法中正确的是（　　）A．该粒子在M点的动能一定小于在N点的动能B．该粒子在M点的电势能一定小于在N点的电势能C．M点的电势一定高于N点的电势D．该粒子在M点的加速度一定大于在N点的加速度