Choose the sentence with the incorrect use of the coordinate clause. She is a great singer, but she is also a great dancer.

She is a great singer, but she is also a great dancer.

I went to the store and bought some milk.

I love reading books, and I also love writing stories.

He is a good teacher, but his classes are boring sometimes.

He is a good teacher, but his classes are boring sometimes.

Explanation: The clause "but his classes are boring sometimes" contrasts poorly with "he is a good teacher." It introduces a contradictory statement that diminishes clarity.