The answers to the clues below will have something in common.

1. Majors
2. Soldier on
3. Certain racers
4. Expression of total bewidlerment
5. Graduation, marriage, and retirement, for three
6. Very slowly
7. Certain collectors
8. Criterion

Answers:

1. Big leagues
2. Put one foot in front of the other.
3. Hotrods
4. "I can't fathom it."
5. Milestones
6. Inch by inch 
7. Meter maids
8. Yardstick

Credit: NY Times Crossword
A.J. Santora
MEASURING UP