Did you ever wonder how some of your favorite foods, products or toys came about? Believe it or not, they may have been an accident, or a failure of some other intention. Below, we found three mistakes we're thankful for turned out to be what they are.

1. Most historians hold that the Chinese invented fireworks in the 9^th century when they discovered how to make gunpowder. Story has it that a Chinese cook accidentally mixed together what were then considered common kitchen items and noticed they burnt. When put tightly in a bamboo tube and lit, it blew up.

2. In May of 1886, a law led John Pemberton, a pharmacist(药剂师), to rewrite the formula(配方) for "Pemberton's French Wine Coca", his popular headache treatment. Containing sugar instead of wine as a sweetener, the outcome became something for Coke, which was later mixed with carbonated(碳酸) water. His bookkeeper suggested the name Coca-Cola because he thought the two C's would look good together, which is how what we call Coca-Cola, a world-wide drink came into being.

3. During World WarⅡ, scientists at the University of Birmingham invented the magnetron(磁控管)—an important heat-producing part of the microwave oven. While working for Raytheon Corporation after the war, the American engineer Percy Spencer was testing the magnetron when a chocolate bar in his pocket melted. He went on to test other foods including popcorn kernels(仁), and found it to be a much more efficient way to cook. In 1947 Raytheon came out with the first restaurant microwave oven, which was six feet tall and weighed 750 lbs.

    Different countries have different customs(风俗) in the world. It's very important for us to know about them.

    When you go to the US, someone often says to you "give me five". What should you do? Do not get five dollars from your pocket! It will make others laugh! The person is not asking for your money, but your fingers.

    In the US, "give me five" or "give me the high five" is a popular gesture. You can see it often in films or on TV. It means hitting(敲打) each other's right hands together.

    People do it when they meet for the first time or something happy happens. For example, a student good grades in exams. If a football teams wins a game, the players will give high fives to everyone around to celebrate.

    This gesture may come from the old Roman gesture of raising the right arm for the empor. This showed the person raising his arm did not have a knife in his hand.

    Why not try to give the high five to your friends?

    We use emojis in our talks all the time. Do you know about their meanings? Let's have a look.

    But some emojis may have different meanings in China. Here are two examples.

    It looks friendly to us, but it can be someone laughing at you.

    People sometimes use this emoji to show that they don't want to talk to you anymore.

    People all over the world can understand the emojis, but in different countries they may have more meanings, we should be careful about how we use them.

    Many of you have watched a Superman cartoon or movie. But did you know he first appeared in comics（连环漫画）? Do you want to learn more about popular comic books around the world? Take a look!

    Do you find reading boring? Have a read of some comic books. You will learn to love their colorful pictures and simple language.

    Comic books usually tell stories through cartoons. The US and Japan have some great comic books. But they are not the same.

    Their names are different. People say "comic books" in the US but "manga" in Japan.

    American comics are often about superheroes—characters like Superman and Spider Man. So action is a major part of American comics. But Japanese manga like to tell stories of ordinary people. Luffy in One Piece（《海贼王》）is such an example.

    American comics make people excited with super powers, while Japanese manga comfort（安慰）people with moving stories. Natsume's Book of Friends is about a teenage boy. He can see spirits（精灵）. He is confused （困惑的）at first but later he makes friends with spirits.

    you are not interested in these two kinds, why not try some from China? Xia Da, 32, is a great comic book artist from China. Some of her comics are about school life. Others show the beauty of Chinese culture.

    When one door of happiness closes, another opens. However, we often look at the 1 door so long that we can't see the one that has been opened for us. It's true that we don't know 2 we've got until we lose it, and it's also true that we don't know what we've been 3 until it goes away.

    Giving someone all your 4 doesn't mean that they'll love you back. Don't expect love in return. Just 5 for it to grow in their hearts.

    There are many moments in life when you miss someone so much that you want to bring them into your 6 and hug them for real! Dream what you want to dream, go where you want to go, and 7 what you want to be, 8 you have only one life and one chance to do all the things you want to do.

    Happiness lies in those who have cried, those who have been hurt, those who have searched, and those who have tried, for only they can understand the 9 of their lives. The 10 future will always be based on a forgotten past. You can't go on well in your life until you let your past failure and heartaches go.