A:①②
B:③④
C:①③
D:②④
(1 )∠C′EF=32°;
(2 )∠BFD=148°;
(3 )∠BGE=64°;
(4 )EG=GF.
要得到函数y=cos12x的图象,只需将函数y=sin12x的图象沿x轴( )