He used to _____ in a village, but now he has been used to _____ in the big city.
请用笔画线表示导线,将如图所示的电灯和开关正确接入家庭电路中.
如图,在▱ABCD中,BE=DF.求证:AE=CF.
①思维和存在具有同一性 ②实践是认识的目的和归宿
③实践是认识的基础 ④人脑是意识产生的物质基础