焊机型号BX3-300中,“300”表示()。
A.焊接电流300A
B.额定电流300A
C.初级电流300A
D.短路电流300A
参考答案:B
(2013·高考湖北卷)Don’t defend him any more.It’s obvious that he________destroyed the fence of the garden even without apology.
A.accidentally
B.carelessly
C.deliberately
D.clumsily
对酸性氧化球团矿的焙烧效果而言,赤铁矿优于磁铁矿。