单项选择题
A.1s B.3s C.5s D.10s
A.0.2Erl(正常)和0.4Erl(异常) B.0.3Erl(正常)和0.6Erl(异常) C.0.4Erl(正常)和0.8Erl(异常) D.0.4Erl(正常)和0.6Erl(异常)