Listen, to what's said to the spelling-test assessor (4,2,5)
I believe the answer is:
mark my words
I'm afraid I can't explain this answer.
Can you help me to learn more?
(Other definitions for mark my words that I've seen before include "what my tutor will do" , "Heed me" , "how teacher would correct the writer's vocabulary" , "believe me!" , "Remember what I say!" .)