odd and even index in cell

A={[113],[112],[42],[29],[113],[69],[86],[9],[0]};
B={[18],[14],[5],[39],[27],[11],[9],[7],[0]};

I want put even index in A to zero. New_A should be:

New_A={[113],[0],[42],[0],[113],[0],[86],[0],[0]}

Also put odd index in B to zero. New_B should be:

B={[0],[14],[0],[39],[0],[11],[0],[7],[0]};

Answer 1

[KSSV]

A={[113],[112],[42],[29],[113],[69],[86],[9],[0]};
B={[18],[14],[5],[39],[27],[11],[9],[7],[0]};

A(2:2:end) = {0} ;
B(1:2:end) = {0} ;