请用笔画线将电路原理图连接完整,使工作电路能正常工作(与触点的接线只能接在静触点上,图中已给出静触点D、E、F、G的四根引线;连线不能交叉)
夜晚光照强度减弱,光敏电阻的阻值增大,电路中的电流减小,电磁铁的磁性减弱,衔铁被弹簧拉起,使衔铁与静触点E、D接触,此时蓄电池与LED路灯组成闭合电路.据此连接电路如下图所示:
阅读短文,判断正误,正确的在题前打T,错误的打F Helen is an English school girl. She’s eleven years old. Now she and her parents are in Jinan. Her parents teach English in our school. They are very kind. Helen is a good pupil. She’s good at maths. We are good friends. She’s clever and beautiful . Now she can speak a little Chinese.(1)Helen is from America. ____ (2)Her parents are English teachers____ (3)Helen is in Beijing now.____ (4)She isn’t good at maths.____(5)She can speak a lot of Chinese.____