抛硬币怎么接住:我想做一个科技小制作
装收音机,万用表.
太阳能电风扇! 做法 先买一个电风扇 ...................................................................................................
....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................再买两个太阳能电池装进去 就完成了 是不是很容易呢?
做个小电铃,别看它貌不惊人,可涉及最基本的电磁学知识,我的孩子在小三时就以小电铃获区一等奖。
作遥控,作成以后可以自己玩。