The letters/numbers follow a definite pattern. Find the missing letter/number to complete the pattern.
(1) _bcc _ac _aabb_ ab _cc
(1) bacab
(2) bcaca
(3) aabca
(4) abaca
(2) gfe _2g _e22_fe2_0 _22
(1) e2fg2
(2) 2fg2g
(3) e2g2e
(4) 2fg2e
(3) 00_0_1_0_0_1
(1) 10010
(2) 01011
(3) 01100
(4) 00111
(1) (1) bacab
(2) (4) 2fg2e
(3) (1) 10010