instruction: Is the next sentence syntactically and semantically acceptable?

Know yourself!

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

John wants to come up with as good a solution as Christine did.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Calculus is difficult for me to concentrate on.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

She bought John's book.

response:
acceptable