The following pairs of words share an unusual quality. Can you determine what it is?

 NAG  RAM
 NOT  HER
 DOLE  SCENT
 LIE  NATION
 EROS  PACE
 POLO  GIST
 WEST  RUCK

HINT:
A single letter will change each clue into a single word.

Answers:

Adding an A at the beginning and then combining the two words together gives new words:

ANAGRAM
ANOTHER
ADOLESCENT
ALIENATION
AEROSPACE
APOLOGIST
AWESTRUCK 

Credit: GAMES Magazine
February, 1986
N. M. Meyer
A+