交流电动机的主要优点是结构简单和供电方便。一般采用()交流感应电动机。
参考答案:三相
It is helpful for children to form a good habit by asking them to _____ all the toys after they finish playing.
A.put off
B.put down
C.put away
D.put out
CO中毒机制最主要是()
A.交感神经过度兴奋
B.迷走神经过度兴奋
C.COHb蓄积
D.高铁血红蛋白蓄积
E.抑制胆碱酯酶