( 3
1
()( ()( ()(
()( ()( ()()
2
(ABB) __ ____ ____ ____ _____ _____
(AABB)__ ____ ___ ____ ____ ____
(ABAB)__ ____ ___ ____ ____ ____
(ABCC)__ ____ ___ ____ _____ ___
(AABC) __ ____ ____ ____ ___
_____
3:
___ ____ ___ ____ ____ ____
__ ____ ____ ____ _____ _____
___ _____ ____ ____ _____ ____
4( ):
____ ____ _____ _____ _____ ____
____ ______ ____ ______ ______
____
___ ______ ____ ______ _____
_______
