3,3,6,(),21,33,48。
A.9
B.12
C.15
D.18
:3,6,12,2l,33,()A.44 B.46 C.48D.50
:3,8,1,12,21,()。 A.34 B.9 C.33 D.11
3, 5, 7, 9, 13, 15, 21, 23, ()。A.29 B.31 C.33 D.35
3,6,12,2l,33,() A.44B.46C.48 D.50
3,5,7,9,13,15,21,23,()。 A.29B.31C.33D.35
3,5,9,13,21,25,()A.27B.29C.31 D.33