单项选择题
A.±1.0Hz B.±0.5Hz C.±0.2Hz D.±0.1Hz
A.3% B.2.4% C.1.6% D.1.2%
A.1% B.2% C.4% D.5%
A.0.8~1.0 B.0.9~9.5 C.0.95~1.0 D.0.85~0.95
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