阅读材料,思考并回答下列问题:
读一读,连线。
①-How many pencils? - Three pencils.____ a.
②- How many books? - One book.____ b.
③- How many rubbers? - Two rubbers. ____ c.
变压器是一种重要的电器设备,对变压器的认识正确的是 ( )
如图是四种微粒结构示意图,下列有关各微粒的说法中,错误的是( )