instruction: Is the next sentence syntactically and semantically acceptable?

The cat was being eating.

response: unacceptable

instruction: Is the next sentence syntactically and semantically acceptable?

John kept him busy.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

I was not reading a book when you came in.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

The ball lies completely in the box.

response:
acceptable