读句子,判断正“√”,误 “×”( )(1)She has the flu.( )(2)John went swimming last Saturday.( )(3)Chen Jie went skiing on her holiday.( )(4)Amy watered the flowers yesterday.( )(5)John climbed a mountain last summer holiday.
(明辨)奥斯特实验证明了电流周围存在着磁场。
(明辨)电磁铁的磁性强弱与电流方向、电流大小和匝数都有关。
(明辨)通电导体周围一定存在磁场。
(明辨)导体周围存在磁场。
(明辨)磁体和电流周围都存在磁场,磁场中不同点的磁场方向一般不同。