電動車
上游
鋰電池-隔離膜
#<StockCompany::ActiveRecord_Associations_CollectionProxy:0x0000768806a63858>
中游
鋰電池
#<StockCompany::ActiveRecord_Associations_CollectionProxy:0x0000768806ae9430>
減速齒輪
#<StockCompany::ActiveRecord_Associations_CollectionProxy:0x0000768806b1c4e8>
下游