Do you suppose Darwin, one of the greatest scientists of all time, really did fools' (傻瓜的) experiments? Or did he do experiments that were so simple and basic (基础的) that other people just thought they were foolish?

    Sometimes, people think they already know the answer to a question or a problem．Sometimes, they really do know an answer, but without thinking it is important．

    Charles Darwin didn't just think he knew something．And, he believed all things could be important no matter how simple they seemed to be．

    Suppose you drop pieces of paper that are of exactly the same size and shape．If you drop them at the same time in the same place, they will fall in the same way．Now make one of the sheets of paper into a tight little ball and let it drop along with the other pieces．What happens? You have done an experiment that is so simple that you might think it couldn't be worth anything．

    But this simple experiment is important．It explains part of our present day understandings of physics (物理学) ideas that were worked out long ago by Galileo and Newton．And these understandings set aside some of ancient Greek (古希腊的) physics．

    The scientist sometimes stops to look at very simple things and to think very hard about them．Even the simplest idea, which we might think is foolish, can shake the foundations (基础) of science．

    Two men are walking in the park. One is Mr. Brown, a worker, the other is Mr. Black. Mr. Brown is going to a chair. It is beside the road. Mr. Black is after him. Mr. Brown finds Mr. Black. Now Mr. Black begins to walk faster (更快), because he wants to get to the chair before Mr. Black. Now Mr. Black begins to walk faster because he also wants to get to the chair first. Then they both run. Mr. Black runs faster than (比) Mr. Brown. So he gets to the chair first and sits down on it. Mr. Brown runs after Mr. Black. When he gets to the chair, he sees Mr. Black sitting on it. He is sorry to show a notice (通知) with the words "Wet Paint (油漆未干)" to Mr. Black. Now Mr. Black knows why Mr. Brown is going to the chair.

    Megan and Mia are sisters. They are the same age, have the same last name, and live in the same house. You might think the sisters are twins, but they aren't. They started their lives in very different places.

    Before Mia was born, her parents decided to adopt(收获)a little girl from China. Their plan was to adopt a girl: she would be an age in between their son, Michael, and the new baby. But that's not how it worked out. Mia was born, and soon. Their parents learned they could go to China to adopt Megan She was three months younger than baby Mia.

    The girls are in the same grade, but not in the same class. They don't share clothes or toys or even hobbies. But they share some of the same friends. And when the sisters fight, it's usually about friends. "Sometimes one of us thinks that the other is stealing(偷)friends, so we fight," Megan says.

    The girls have their own rooms. "If I have a bad dream or see a scary（恐怖的）movie, Mia will let me sleep in her room, "Megan says. "We can give each other help and advice," Mia says." And we keep each other's secrets."

    Megan says she is so thankful for her family, but sometimes she feels sad. "I feel sad when people say, "You don't look like them!" she says. "Maybe you can't see it right away, but it's so clear that Mia and I are sisters. We'll always be there for each other."

    Is handwriting (书写) important? Yes, the 10-year-old girl Alyssa thinks so. She is a fifth-grade student from Mason County, the USA. She's the champion (冠军) for her grade level in the National Handwriting Contest in 2012.

    After she got the news, Alyssa was surprised that she could be the first. "I'm really happy," she said. "I'm really surprised, too. I didn't know I was that good."

    To enter (参加) the contest, each student had to write the sentence (句子) "The quick brown fox jumps over the lazy dog". It is a common English sentence, but it uses every letter of the English alphabet. Teachers were invited to be judges. They could decide who wins the contest.

    Alyssa enjoys handwriting, and wants to write adventure (冒险) stories when she gets older. "From the third grade we started learning handwriting," Alyssa said. "All the letters look pretty. It makes me think of art."