A . 低潮潮高+潮差×[1+cos(t/T×180)]/2
B . 高潮潮高+潮差×[1-cos(t/T×180)]/2
C . 高潮潮高-潮差×[1+cos(t/T×180)]/2
D . 低潮潮高+潮差×[1-cos(t/T×180)]/2