( )÷( )=4
16÷4=4
20÷5=4
24÷6=4
28÷7=4
32÷8=4
36÷9=4
探究影响电磁铁磁性强弱的因素时,按如图所示电路进行实验,发现电磁铁A吸引大头针的数目比B多.此实验说明影响电磁铁磁性强弱的因素是____
—Hey, Tom. ______ the waste paper and throw it into the bin. You can't throw it here.
—Sorry.