All a joke! Hey everyone, let's put her in a closet before teacher comes
But this is the day, the scientists predict, they say, they know, the sun...
Margot...! She's still in the closet where we locked her.
The conflict is Man .vs. Society that William and the class bully Margot because she got to see the sun. She used to live on Earth and the others lived on Venus all their lives. So Margot got to see the sun and remember what it looks like. The sun comes out every 7 years for 2 hours and all of the kids except Margot only was able to see the sun at 3 years old. The quote "All a joke! Hey everyone let's put her in a closet before teacher comes." shows the conflict of the story.
The character trait of William is that he is a bully just because from the quotes: "let's put her in a closet before teacher comes" and the quote "speak when you are spoken to. He gave her a shove." This shows that William is a person who is a bully and bullies people who are different than him.
The class are now all stunned because they just remembered about Margot still in the closet and how they were wrong and she was right about the sun. In the end just because someone is different than you doesn't mean you should bully them.