The governors were joined by Mr Hunter and his management team.亨特先生及他率领的管理小组加入了州长们的队伍。The two policemen were joined by another policeman also carrying a pistol.另一名持枪警察和那两名警察会合了。His inspiration to fly came even before he ...
两个磁体的N极和S极互相吸引.The N pole and S pole of two magnets will attract each other.为了做成电磁体你需要对金属线送电.To make an electromagnet you need to send a current through the wire.棒形或马蹄形磁体称为永磁体.A bar on horseshoe magnet is called a perman...