Here is the item:
Tiffany __________ through all of Professor Olefke's 8 a.m. astronomy lectures; at the end of the semester, she would have a better chance escaping the gravity of a black hole than passing the course.

The blank requires the simple past of sleep, an irregular verb. You chose slept, the correct form. Hallelujah!

Verb Simple
Present
Simple
Past
Past
Participle
sleep sleep(s) slept slept

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