1. If you are interested <font color="#ff0000">to know</font> more about the town's history, you should visit the museum.<br/><br/>2. If you are interested <font color="#ff0000">in knowing</font> more about the town's history, you should visit the museum.<br/><br/>3. I'm really interested <font color="#ff0000">to visit </font>an art museum.<br/><br/>4. I'm really interested <font color="#ff0000">in </font><font color="#ff0000">visiting </font>an art museum.<br/><br/>Which of the above sentences is NOT acceptable?