1. The same three letters, in the same order, will complete the partial words below.

NA _ _ _
CH _ _ _
OL _ _ _
AL _ _ _
DR _ _ _

2. The same five-letter word can precede each of the words below:

_ _ _ _ _ LIE
_ _ _ _ _ PIN
_ _ _ _ _ AGE
_ _ _ _ _ WAY
_ _ _ _ _ DOG


Answers:

1. The letters are IVE:

NAIVE / CHIVE / OLIVE / ALIVE / DRIVE 

2. The word is UNDER:

UNDERLIE / UNDERPIN /  UNDERAGE / UNDER WAY / UNDERDOG