A.-30° B.30° C.90° D.120°
A.110V B.100V C.200V D.150V
A.先小后大、先輕后重、先低后高 B.先大后小、先重后輕、先高后低 C.先小后大、先重后輕、先高后低 D.先大后小、先重后輕、先低后高