TASK DEFINITION: You're given a sentence and your task is to classify whether the sentence is acceptable or not. Any sentence which is grammatically correct, has a naturalistic text, is written by a native speaker and which minimizes superfluous content is acceptable, otherwise unacceptable. If the sentence is acceptable then write "acceptable", otherwise "unacceptable".
PROBLEM: How much harder has it rained, when you see a faster flow in the river?

SOLUTION: acceptable

PROBLEM: She knocked herself on the head with a zucchini.

SOLUTION: acceptable

PROBLEM: Students study English for 4 hours a day.

SOLUTION:
acceptable