纳米粒子表面原子易与其他原子相结合而稳定下来,具有很高的:
A. 化学稳定性
B. 化学反应性
C. 化学惰性
D. 化学活性
超导体在超导状态下的电流可以无穷大。( )
A. 对
B. 错
[音频]•12.A.Open. B.Friendly.C.Selfish. D.Reserved. •13.A.Theystayquiet. B.Theyreadabook. C.Theytalkabouttheweather. D.Theychatwithfellowpassengers. •14.A.Shewasalwaystreatedasaforeigner. B.ShewaseagertovisitanEnglishcastle. C.Shewasneverinvitedtoacolleague'shome. D.Shewasunwillingtomakefriendswithworkmates. 15.A.Housesaremuchmorequiet. B.Housesprovidemoreprivacy. C.Theywanttohavemorespace. D.Theywantagardenoftheirown.
三相异步电机的定子铁心中三相绕组空间相隔( )
A. 90度
B. 120度
C. 180度
D. 60度