题目

IPad vs Textbooks What if you could have your whole backpack at the touch of your fingertips? In the first month of the Apple iPads release, 25million were sold! People all over the world use iPads for all sorts of different things, but one of their finest qualities is the ability to be a textbook. ___36.____ To begin with, iPad are less expensive. Textbooks become outdated and schools have to buy new books, but with an iPad schools can update them for free. __37.___ Schools don’t have to spend $500 every year for iPads because they last a while and can be updated. ___38.__ Students 如图所示，电源电压保持不变，闭合开关S后，当滑片P向上移动时，下列判断正确的是 [　　] A．三只电表的示数都变大 B．三只电表的示数都变小 C．电表A1的示数变小，电表V、A2的示数都不变 D．电表A1、A2的示数都变小，电表V的示数不变