Veronica was an only child. Even as a child, she decided that she was going to be a doctor. All her dolls became her patients. All her dollhouses became hospitals for her patients. She spent her early childhood treating her patients for all kinds of diseases and injuries. She saved all of them and billed none of them.

Veronica got straight A's in high school and college, because she knew that good grades would help her get into a good medical school. She graduated from medical school near the top of her class. She became a pediatrician（儿科医师）. She got married and had two kids, one boy and one girl. Veronica's husband David was an architect and a great cook. Her children did their homework without being told. They got straight A's in school. They ate all their vegetables without complaining. They were perfect little children, except for one thing: They argued with each other constantly.

Veronica got home at 4:30 p.m. today. David gave her a big kiss and a hug. Then her kids gave her a kiss and a hug. She went upstairs and changed into shorts and a T-shirt. When she returned, the kids were waiting for her in the living room to talk about their day in school.

Marvin, 10, said that today his biology teacher helped them cut up dead frogs. They smelled bad, but he enjoyed seeing their little body parts, like their lungs and heart. "I like biology," Marvin said. "I want to be a biologist, an animal doctor, and an inventor when I grow up. I'm going to invent a pill so that animals all learn to live together without eating each other all the time."

"You're crazy!" exclaimed Rebecca. "What are the animals going to eat if they don't eat each other?" 

"You don't know anything. You're a girl and you're only nine," taunted Marvin. 

"Marvin, be polite to your sister," Veronica admonished. 

"Yes, ma'am," he said. "I apologize, dear little sister." 

"That didn't sound very sincere, mommy," Rebecca complained. 

"Okay, here's how I'll keep the animals from eating each other. I already thought of that, of course. The solution is a pill that will make all animals like to eat grass, like the cows and sheep do. That way no more animals will eat each other, and kids won't have to mow the lawn any more. So, that will kill two birds with one stone." 

"Well, that's very clever," Veronica told Marvin. 

"Now, tell us about your day, Rebecca," Veronica said. 

"Well, as you know, mommy, I'm going to be a real doctor like you, not a mad scientist like somebody I know," Rebecca started, and then stuck her tongue out at her brother.