A.0.9(滯后)~0.95(超前) B.0.9(滯后)~0.9(超前) C.0.85(滯后)~0.95(超前) D.0.95(滯后)~0.9(超前)
A.-3%+3% B.-3%+2% C.-2%+2% D.-2%+3%
A.18 B.19 C.20 D.21