The author uses the result of Gallup poll to argue that
A．the first ladies in America are respected by the whole nation.
B．Rosalynn is not as good as Nancy Reagan in the 1980s.
C．Gallup poll is an effective organization to collect public opinions.
D．today's famous people are created for their well-knowness.

判断题励磁绕组断线的他励直流电动机，额定负载起动时，将出现电流过大情况。()

未分类题The phrase 'putting their heads together'(Lines 7-8, Paragraph 3)meansA．making efforts collectively.B．always getting together.C．thinking in the same way.D．chatting together.

判断题三相异步电动机根据转子结构的不同，分为笼型异步电动机和绕线型异步电动机。()

未分类题According to Brand, older workers suffered less than young laid-off workers becauseA．young workers feel more humiliated at being laid off than older people.B．older workers want to retire earlier to enjoy their life.C．young workers cannot get used to the life after being laid off.D．older workers do not worry about their retirement life after being laid off.

判断题同一台异步电动机，用三角形接法起动和用星型接法起动相比，前者的起动电流(线电流)是后者的3倍;前者的起动转矩是后者的3倍。()