Q-A (A flash mob is a sudden public gathering of people which) is organized using email, Twitter, and social networking sites. At the gathering, people participate in pointless activities. (It only lasts for a short time.)
Q-B (Supporters would say that flash mobs encourage) people to come together and express themselves in a unique way, (whereas critics argue that flash mobs prevent) other people from trying to go about their business.
Q-C I would not participate in the event for the following reasons. First, it would bother and even hurt other people. Many people come to the festival and enjoy it differently. Therefore, a snowball fight would be a nuisance to some of them. In addition, there are many sophisticated ice sculptures in the park. What if we happened to damage them? We could not make up for the damage done by our carelessness. Lastly, even worse than these is the fact that a snowball fight is something children do. A sensible person would know better than to do such childish things. (100 words)