"Before we start class today, I'd like to explain one thing.", the science teacher announced at the beginning of first period. "I'm sure you've all heard on the news about the new planet that's been discovered, the tenth in our solar system. I'm sure there are lots of questions about it, especially if you're wanting to write about this for your article due this week. So if anyone's wondering about it, I'll try to explain things as best I can and clear up any misconceptions you may have. Raise your hands, please"
A boy in the second row quickly raised his hand.
"Yes?", said the teacher.
"Is it true that they've found intelligent life on this planet?", he asked.
"Well, it depends on how you define 'intelligent.'", the teacher replied. "The beings are civilized, yes, but compared to us, they're not really all that intelligent. Our technology is much more advanced than theirs is"
A girl behind him raised her hand next. After the teacher called on her, she asked, "What was the name of the planet again"
"Those who discovered it have named it Reggantal.", the teacher explained. "But the inhabitants of the planet called it something else. Actually, scientists think they had many names for it, as this planet contains many diverse cultures and different languages. We were able to decipher one of their major languages, you see, since they're so primitive. However, their name for it has slipped my mind at the moment...Maybe it'll come back to me"
"What do the creatures there look like?", a boy in the back of the room asked without raising his hand.
The teacher answered anyway. "Just like on our planet, there are a variety of different species on Reggantal; many different types of creatures. Do you mean the dominant species"
"The ones who were civilized but primitive.", answered the boy.
"I thought so.", the teacher said. "They look somewhat similar to us, actually; their bodies are built in bilateral symmetry. Does anyone know what that means"
The class brain, a dark-haired girl in the front row, answered. "It means two of everything. Two arms, two legs, two eyes, two ears, etc"
"You're correct.", said the teacher. "Just like us, these creatures have bilateral symmetry. Two arms and two legs; they even walk upright on those legs. Although I think the beings tend to be slightly shorter than us on average"
The same dark-haired girl now had her hand raised. "What's the atmosphere composed of?", she asked the teacher.
"Mostly oxygen, again like our planet.", the teacher replied. "Probably because most beings need oxygen to survive. There's also some nitrogen in it, I think"
The teacher was about to answer another question when he noticed the clock. "Oh, we've been spending too much time on this; we need to start the lesson soon. Okay, last question." He pointed to a tall boy in the third row. "How far away is Reggantal?", he asked.
"Good question.", said the teacher. "I'm not really that good with remembering statistics, but if memory serves, I think it was about 143,600,000,000 quadrilles.
The teacher noticed that there were a few other hands raised, but instead he said, "That was the last question, we need to start class now. If you want to know more, look it up. It's all over the news lately. Now please open your textbooks to last night's homework"
The teacher sat back and listened to pages rustling as the students opened their books. Suddenly, he remembered. "Wait a second, class.", he said. "I've just remembered what the inhabitants of Reggantal call their planet"
"What do they call it?", someone asked.
"Earth.", the teacher replied.

A quadrille is two-fifths of a mile.