A.兩個(gè)正向圓形磁場(chǎng) B.無(wú)法確定 C.兩個(gè)反向圓形磁場(chǎng) D.一個(gè)正向圓形磁場(chǎng)和一個(gè)反向圓形磁場(chǎng)
A. ZLJ B. ZLF C. ZCF D. ZKC