下列说法中正确的是[ ]
A．地球周围存在着磁场
B．磁铁周围存在着磁场
C．导体周围存在着磁场
D．电流周围存在着磁场
ABD
—I'll go to Beijing for the coming summer holiday.
—_____. [ ]
A. Thank you
B. It doesn't matter
C. The same to you
D. Have a good time
回转性好的船舶则稳性就好，回转性差则稳性也差。
