instruction: Is the next sentence syntactically and semantically acceptable?

My brother likes collecting jazz records.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

There is a riot in the park.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

He bought these flowers for Aaron.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Bill floated down the river for hours.

response:
acceptable