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如图甲所示,在2015年某工厂要研发一种新型材料,要求对该材料的承受的撞击力进行测试.在测试时将材料样品(不计质量)平放在压力传感器上,闭合开关s,由静止自由释放重物,经撞击后样品材料仍完好无损.从重物开始下落到撞击样品的这个过程中,电流表的示数I随时间t变化的图象如图乙所示,压力传感器的电阻R随压力F变化的图象如图丙所示.电源的电压=24V,定值电阻R0=10Ω.求:


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   Children who spend more time reading with their parents have a greater chance of becoming better readers than those who don’t. With the help from their parents, children can learn techniques to improve their reading skills.
   “A lot of parents think after their child learns to read, they should stop reading to them,” Donna George said. “They are sadly mistaken.”
   George offers her services to parents at the Title I Learning Centers. She said reading aloud to children may be the most valuable thing parents can do. “It is better for children to hear things at a higher level than where they are,” George said. “Parents are their child’s first teacher.” Parents help their children build listening, phonics, comprehension and vocabulary skills when they read aloud to them.
Before parents can identify reading problems, they should escape the enemy
   —television and limit the time their children spend watching television. George suggested not allowing kids to have a TV in their bedrooms, setting a schedule of when kids can watch or keeping a list of how many programs children watch. Louise Joines said while her 14-year-old daughter and 10-year-old son enjoy reading, the television sometimes becomes a distraction. So she tries to build the situation by suggesting books the entire family will enjoy reading together, like the Harry Potter series.
   Parents who do not read themselves should not count on their children being interested in it. If parents would read to their children at least 15 minutes every day, children would not have so many problems in school. It is the parents’ job to help build that desire in their children, and of course to know what kind of books to read is also important.