OMISSION

1. Can you think of a four-letter word that can be preceded by O to make an unrelated five-letter word?
    _ _ _ _
O _ _ _ _ _

2. Can you think of a five-letter word that can be preceded by O to make an unrelated six-letter word?

    _ _ _ _ _
O _ _ _ _ _

HINTS:
1. First letter Z
2. First letter R

Answers:

1.    ZONE
    OZONE 

2.    RANGE
    ORANGE