The young boy saw me, or rather, he saw the car and quickly ran up to me, eager to sell his bunches of bananas and bags of peanuts. Though he appeared to be about twelve, he seemed to have already known the bitterness of life. "Bananas 300 naira. Peanuts 200 naira." He said in a low voice. I bargained him down to 200 for the fruit and nuts. When he agreed, I handed him a 500 naira bill. He didn't have change. So I told him not to worry. He said thanks and smiled a row of perfect teeth.

    When, two weeks later, I saw the boy again, I was more aware of my position in a society where it's not that uncommon to see a little boy who should be in school standing on the corner selling fruit in the burning sun. My parents had raised me to be aware of the advantage we had been afforded and the responsibility it brought to us.

I pulled over and rolled down my window. He had a bunch of bananas and a bag of peanuts ready. I waved them away. "What's up?" asked him. "I…I don't have money to buy books for school." I reached into my pocket and handed him two fresh 500 naira bills. "Will this help?" I asked. He looked around nervously before taking the money. One thousand naira was a lot of money to someone whose family probably made about 5,000 naira or less each year. "Thank you, sir." he said. "Thank you very much!"

    When driving home, I wondered if my little friend actually used the money for schoolbooks. What if he's a cheat? And then I wondered why I did it. Did I do it to make myself feel better? Was I using him? I didn't know his name or the least bit about him, nor did I think to ask.

    Over the next six months, I was busy working in a news agency in northern Nigeria. Sometime after I returned, I went out for a drive. When I was about to pull over, the boy suddenly appeared by my window with a big smile ready on his face.

"Oh, gosh! Long time."

"Are you in school now?" I asked.

    He nodded.

"That's good," I said. A silence fell as we looked at each other, and then I realized what he wanted. "Here," I held out a 500 naira bill. "Take this." He shook his head and stepped back as if hurt. "What's wrong?" I asked. "It's a gift."

He shook his head again and brought his hand from behind his back. His face shone with sweat. He dropped a bunch of bananas and a bag of peanuts in the front seat before he said, "I've been waiting to give these to you."

    I always wondered how people would react if I tried to approach a total stranger for help in a busy place like a street corner or in a noisy mall. I have always hurried past a stranger who tried to catch my attention in a busy place or when I am rushing around.

    Yesterday, I was in a busy shopping mall buying a large piece of luggage because I just had the time to do it after many days of planning. After the purchase in one of the large shops, I picked up my phone from my pocket to call my driver waiting in the parking lot but my phone was dead.

    I then requested the shop assistant who had just sold me the luggage to ring the number of my driver for me and she replied that it was the shop policy that they cannot use mobile phones while working in the shop.

    I got out of the shop onto the busy street in front and approached a young mother with her two kids to make a request. As soon as I said “Excuse me, madam”, she grabbed both her kids and ran. I felt like a kidnapper.

    I stood there, wondering how many times I had reacted to strangers like the young mum. I stood there in the busy street with people rushing by, looking at their faces to see if there was a sign of kindness on their faces.

    I saw a man pretty shabbily dressed. He seemed to have noticed me and I just stopped him expecting him to rush past. My request escaped the lips. He immediately called the number of my driver and waited till my car came to be sure I was picked up, and he turned around before I could thank him adequately and was gone. I was surprised by his kindness and hope I will do likewise (同样地) to strangers who try to catch my attention from now on.

    Dolphin or not a dolphin? That is the question! You see, there are several types of dolphins. Some are saltwater dolphins while others are river dolphins.

    "What are the 32 types of dolphins?" When people are asking the question, they are actually referring to the saltwater dolphins in oceans and seas. The river dolphins living in fresh water are not included in these species. But what would be the answer in this case if we ask. "Dolphin or not a dolphin?" The answer would obviously be yes. River dolphins still belong to the dolphin family.

    Among the 32 types of dolphins do not actually wear the word "dolphin" in their names, such as the tucuxi, while others actually have the word "whale" as part of their names even if they are not whales but in fact, belong to the dolphin family, for example, the melon-headed whale and the killer whale. So what would be the answer to the question "Dolphin or not a dolphin?" in these cases? It would be yes. All these species do belong to the dolphin family.

    Another question that people ask is. "Are the sea animals that perform at aquariums(水族馆)all dolphins?" So ,it always seems to come back to the question, "Dolphin or not a dolphin?" Well the answer is no in this case. The sea animals that perform there are not all dolphins. The beluga which people tend to think belong to the dolphin family because they show what seems like a smile, like most dolphins, are in fact a species of the whale family.

    Now that you read these facts about dolphins, you probably realize that certain sea animals may appear to be part of the dolphin species and that others seem to be part of the whale family but in either case, it is not obvious and can be surprising when you identify a sea animal as being a dolphin or not a dolphin. That is the question ！

    After finishing a meal at an American Chinese restaurant you probably expect to receive a handful of fortune cookies after you pay the bill. Fortune cookies are in Chinese restaurants throughout the United States. It's rather satisfying to crack open a cookie at the end of your meal and read your “lucky fortune” on the slip of paper inside.

    The exact origin of the fortune cookie is unknown. It is thought that the tasty snack was the first introduced into San Francisco in 1914, after an immigrant began distributing the cookie with “thank you” notes in them. These “thank you” notes were intended as symbols of appreciation for friends who stood with him through the economic hardship and discrimination of his early life in America.

    There is an alternate origin story. Los Angeles is regarded as the site of the fortune cookie's invention. In this version of the story, David Jung, a Chinese immigrant residing in L. A., is thought to have created the cookie in order to uplift the spirits of the poor and homeless. In 1918, Jung handed out the cookies for free to the poor outside his shop and each cookie contained a strip of paper with an inspirational sentence printed on it.

    Fortune cookies first began to gain popularity in mainstream American culture during WWII. Chinese restaurants would serve them in place of desserts, as desserts were not popular in traditional Chinese cuisine. Today fortune cookies are not tied to Chinese-American culture. In fact, the largest fortune cookie manufacturer is located in the United States and it produces 4.5 million fortune cookies a day —— an evidence to the modern-day popularity of the snack. However, an attempt to introduce the fortune cookie to China in 1992 was a failure, and the cookie was cited for being “too American.”

    So the next time you break open a fortune cookie and read a fortune about the many successes you should expect in your future, remember that the conclusion to your Chinese restaurant meal may not be as Chinese as you think.

    Plants are living things. So can they feel pain? Plants don't feel pain the same way animals and people do, says Anke Steppuhn. She is a scientist at the Free University of Berlin in Germany. "What we define as pain usually has to do with a nervous system," Steppuhn explains. When you put your hand too close to a hot stove, nerve cells send a signal to your brain. Your brain decodes (解码) that signal as pain. This causes you to pull your hand away before any serious damage is done.

    Plants don't have nerves or brains, so they can't feel pain like we do. "But plants do recognize when something is hurting them," Steppuhn says. Because they are rooted to the ground, they can't escape a dangerous situation. So they need other ways of fighting back.

    The biggest threat to a plant's life is getting eaten. Some plants grow sharp little hairs. Other plants produce bad-tasting or even harmful chemicals. These force an attacker to abandon its meal. A plant called bittersweet nightshade does something even smarter, Steppuhn found. When a slug (蛞蝓) chews holes in a nightshade' s leaf, liquid begins dripping (滴) around the wound. It is almost as if the plant were bleeding. The liquid is sugary nectar (花蜜), and it happens to be a favorite food of ants. In their effort to collect the nectar, the ants swarm (蜂拥而至) all over the injured plant. They will attack anything that stands in their way. That includes the slug that damaged the plant in the first place. It's a very clever trick. Whenever a slug attacks a plant, the plant calls an army of ants to kill the slug.

    Nectar isn't the only way plants attract bodyguards. They also release certain chemicals into the air when they are being eaten. People usually can't detect these smells. But wasps (黄蜂) can. When a wasp detects this cry for help, it races to the scene of the crime. If it finds the right kind of insect chewing down on the plant, the wasp will interrupt the attacker's meal. It will do this by laying eggs inside the insect's body!

As I walk into the big room at school, I'm wearing my white coat that doctors usually wear. But I also have on some funny 1 and a messy wig that makes me look like a crazy scientist. My name tag says "Professor Quantum Quirks," which makes people laugh.

Inside the room, there are a lot of 2 getting ready for a science fair. They look excited but also a little 3 . I notice one boy sitting by himself, looking 4 because his science project isn't working right. I go over to him and 5 he's having a hard time with it. I feel bad for him. So, I decide to 6 him by doing a fun experiment together. We 7 a mini volcano using simple things we can find at home. He starts to 8 himself and gets excited when the volcano erupts with bubbly stuff. Other kids see us having fun and come over to 9 . We do more cool experiments with them and everyone is 10 and having a good time.

By the end of the science fair, I 11 my wig and glasses, but I'm still 12 because it was so much fun. I hope the kids keep being 13 about science and discovering new 14 . After all, asking questions and exploring is how we learn and have fun in the world of 15 .