单项选择题
A.同相 B.反相 C.相差90° D.相差-90°
A.0.17% B.0.25% C.0.5% D.1%
A.30.3 B.40.4 C.50.5 D.60.6
A.65%~92% B.65%~75% C.75%~92% D.70%~90%
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