I want to know the answer to the following question:
What two activities did Frédéric do while visiting for a day in Düsseldorf with Mendelssohn and Hiller?
All the background I'm provided with is that "In 1835 Chopin went to Carlsbad, where he spent time with his parents; it was the last time he would see them.". Is that enough to answer the question?
Answer: no