A.63個(gè)VC12; B.126個(gè)VC12; C.252個(gè)VC12; D.210個(gè)VC12;
A.CSC B.OIB4 C.O4CS D.CSBE
A.4個(gè)(4); B.5個(gè)(5); C.6個(gè)(6); D.7個(gè)(7);