题目

The scientists have found out how computers and theInternet are going to(effect) our lives. 答案：【1】affect小华同学在做“探究电磁铁”实验中，用两个相同的大铁钉绕制成电磁铁进行实验，如图所示．①小华同学是通过观察______来确定电磁铁的磁性强弱，由图可知，线圈的匝数越______，电磁铁的磁性越强．②要使图中电磁铁磁性增强，应将滑动变阻器的滑片向______滑动．