Neither of these are phrased in the passive and the second sounds like it could be a command. If they had been phrased "what vegetables are needed?" and "first one buys fresh vegetables", then I could see. Are there reasons that my answers are wrong??
Here's what I put:
Lidia] Ah pues dime, ¿qué verduras necesitan?
[Sonia] Mira, primero compra verduras frescas