Answer:

cee

Answer	Crossword Clue
CEE	Car starter
CEE	Letter grade
CEE	Middling mark

CEE	Not-so-impressive grade
CEE	Can opener?
CEE	In the 70's, usually
CEE	Tragic ending?
CEE	Average grade
CEE	Lincoln center?
CEE	1-3 of a cup?
CEE	...-Lo Green

CEE	Middling grade
CEE	Fair grade
CEE	Bee follower
CEE	Bee chaser?
CEE	Shape of a clamp
CEE	Canada's capital
CEE	Mediocre grade
CEE	Third grade

CEE	Letter on a French hot-water faucet
CEE	Unspectacular grade
CEE	What follows the second letter of the alphabet
CEE	Letter before dee
CEE	So-so grade
CEE	Fair mark
CEE	Mediocre mark
CEE	70-80, usually

CEE	Clamp shape
CEE	Medium grade
CEE	Adequate grade
CEE	Average mark
CEE	Colombian capital?
CEE	California capital?
CEE	Cave opening?
CEE	Decent grade

CEE	2.0 average
CEE	Average, in school
CEE	Cadillac's front or back
CEE	Ho-hum grade
CEE	It's hard in "cash"