4,4,6,12,()
A.30
B.24
C.20
D.18
:1,4,9,15,18,() A.21B.24C.9D.20
6,9,12,18,18,27,(),36,30,()。 A.24,45B.45,24C.27,54D.54,27
1,4,9,15,18,() A.21B.24C.9D.20
6,9,12,18,18,27,(),36,30,()。 A.24,45 B.45,24C.27,54D.54,27
4,4,6,12,() A.308.24C.20D.18
1,4,9,15,18,()A.21B.24C.9D.20