1_ _ _ _ is unique.

Two, five _ _ forgetfulness

0000 _ _ _ is foolproof.

2468 _ _ _ _ is not unique.

1 divided by 2 _ _, divided into two, 5. Take math as a riddle and guess the riddle of idioms.

0________

1________

Two, five _ _ _ _ _

0000____________

2468____________

1 divided by 2 _ _ _ _ _ _ _