采用（）方式来控制铜套厚度。
A、刮削
B、磨削
C、铣削
D、镗削
参考答案：A
I have ______ money than you, but I have _______ friends than you.
A．more, more
B．less, more
C．fewer, more
D．more , less
B．扬声器中的磁铁
C．电磁铁中的铁芯
D．储蓄用的信用卡
