A.-cosx
B.-ycosx
C.cosx
D.ycosx
[单选题]A.-cosxB.-ycosxC.cosxD.ycosx
[单选题]A.B.C.D.
[单选题]A.B.C.D.1
[单选题]A.明显下降B.正常或偏低C.增高或正常D.明显增高E.轻微增高