You will be given a definition of a task first, then some input of the task.
In this task, you're given a context passage. Your job is to generate relevant questions that can be answered by directly referring to the passage.

I remember elaborate " hot air balloons " we built out of baskets and string for our Beanie babies and the yellow car we used to drive around the plastic castle in the backyard playing " Mcdonald's . " I remember spending an entire week once living with my sister in a large refrigerator box that my dad brought us from work . We cut out holes for windows and loved that box to pieces . When my dad finally had to throw it away , we cried .
Output:
Why did they build hot air balloons out of baskets and string ?