Answer:

EFFS

Answer	Crossword Clue
EFFS	Dismal grades
EFFS	Flunking grades
EFFS	Failing marks

EFFS	Report-card blemishes
EFFS	Fluffy trio?
EFFS	Reasons for makeup
EFFS	Report card ruination
EFFS	They keep you from passing
EFFS	Reasons for certain repeats
EFFS	Failing grades
EFFS	40% of fifty?

EFFS	Pair of officers?
EFFS	Pair of duffers?
EFFS	Letters denoting bad grades
EFFS	Two out of fifty?
EFFS	Report card woes
EFFS	Pair of giraffes?
EFFS	Letters before gees
EFFS	Wipes out

EFFS	English letters.
EFFS	Results: Abbr.
EFFS	Letters.
EFFS	Belongings: Abbr.
EFFS	Letters
EFFS	Gee antecedents
EFFS	Offenbach duo
EFFS	Gee preceders

EFFS	Two of fifty?
EFFS	Rotten grades
EFFS	They can make a suer suffer
EFFS	Flunking marks
EFFS	Sign of poor schoolwork
EFFS	Bad grades
EFFS	Pair of ruffians?
EFFS	Pair of buffalo?

EFFS	... off (gets lost)
EFFS	Small apartments, in ads
EFFS	Small apts.
EFFS	Two from fifty?
EFFS	Lousy grades

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.