People eat different things in different parts of the world.

    In south China we eat rice every day. Sometimes we eat it two or three times a day, for breakfast, lunch and supper. We usually eat it with fish, meat and vegetable.

    The Japanese eat rice, too. They also eat a lot of fish. They sometimes eat raw（生的）fish. In Africa, maize（玉米）is the most important food. People there make maize into flour（面粉）.From this flour they make different kinds of bread and cakes.

    In western（西方的）countries such as Britain, Australia and the U.S.A, the most important food is bread or potatoes. People there usually make their bread from wheat flour. They cook the potatoes in different ways. In England the most popular food is fish and chips. Sometimes people cook this food at home, but usually they buy it at the shop. They eat this food at home, in their work place, in the park or on the road. People call it "take-away" food.

    In the rush to get to school, you drop a piece of toast on the floor. Do you throw it away or decide it's still OK to eat? If you're like most people, you eat it. Maybe you follow the “5-second rule”, which says foods are safe to eat if you pick them up within 5 seconds after dropping them. But you might want to think again. Scientists now say that 5 seconds is all it takes for foods to become polluted with enough bacteria to make you sick.

    Bacteria can cause many kinds of illnesses. Some kinds of bacteria can grow on food. If you eat foods on which these bacteria are growing, you can become sick.

    One of these food-borne bacteria is Salmonella. It makes 1.4 million people sick every year. Salmonella is often found in raw eggs and chicken. Cooking kills these bacteria, which is why it is so important to cook eggs, chicken, and other foods thoroughly.

    But how long does it take these bacteria to pollute food? A team of scientists in South Carolina did an experiment. First, they placed an amount of Salmonella on three surfaces: wood, tile, and carpet. They placed a piece of bread and a piece of sausage on each surface for 5, 30, or 60 seconds. After just 5 seconds, both the bread and the sausage picked up enough bacteria to make you sick.

    So, forget the 5-second rule. If your toast drops on the floor, throw it away and get another piece of clean toast. And next time, be careful not to drop it!

    Today, I had the good fortune to join the students from East Silver Spring Elementary School in Maryland as they walked and biked to school in celebration of International Walk to School Day. I want to thank Principal Morrow and the entire ESS community for welcoming me so enthusiastically.

    Walk to School Day is a great opportunity for me to spend time with parents, kids, and teachers and to present our Safe Routes to School program and the First Lady Michelle Obama's Let's Move initiative（倡议）.

    As a father, grandfather and former schoolteacher, I know how important it is that we provide students with safe choice to get to school while promoting exercise and healthy lifestyles. That's why I've embraced the Safe Routes to School program so wholeheartedly since I became Secretary of Transportation.

    You know, we're looking at an increasingly sedentary（久坐的）generation of children. One out of every three kids in America is now overweight. And I admire the First Lady's effort to end this within a generation. Safe Routes to School is a natural partner for Let's Move. For more than 10 years, Safe Routes to School has been making it easier for students to walk and bike from home to school. And ESS, where I walked today, is one of the earliest schools to participate.

    We know this program has been enormously effective because of the steady increase in the number of kids walking or biking to school. And as we made our way down the street this morning I was reminded yet again of this program's extraordinary work.

    Look, walking and biking to school is good for students' health. It's good for the environment. And it's good for the entire community's quality of life.

Everybody wins when kids take Safe Routes to School.

    My students entered the art room with their usual eagerness to see what they would be learning in today's class. Little did they know they were going to be students for a new teaching method that is spreading the nation.

    I often use videos as previews and supplements (补充) to our art lessons providing students with a variety of artists showing their skills in real-life situations outside the classroom. Finding a new painting technique called glue batik(胶水蜡染),  I thought of something new I hadn't tried before!  How awesome would it be to learn a new technique together with artists? The lesson was planned, presented to the students without any introduction or set objectives. I also asked the students to watch and pause the video as often as they needed to.

    They watched as the artist explained and showed her skills, taking notes on her steps and results. After the video, they shared what they felt the artist's objectives were, her end result using art vocabulary as well as the steps they would need to know to present their own examples. Then they began creating their works using the glue batik technique.

    Surfing the Internet a couple of weeks later, I found that the teaching method I used sounded very familiar to a new movement in education called flipped teaching, which was developed by Jonathan Bergmann. He asked his students to watch video lectures at home and do exercises (homework) in class under supervision (监督). He found that grades went up and he also found time for other types of activities, which Bergmann states are more important than the videos.

    Back to my art class, the students were learning to get ideas, make predictions, and explain reasoning to their classmates. Together they compared, asked questions and made discoveries as they presented the technique.

    Chinese scientists recently have produced two monkeys with the same gene, Zhong Zhong and Hua Hua, using the same technique that gave us Dolly the sheep. These monkeys are not actually the first primates(灵长类)to be cloned. Another one named Tetra was produced in the late 1990s by embryo(胚胎)splitting, the division of an early-stage embryo into two or four separate cells to make clones. By contrast, they were each made by replacing an egg cell nucleus(原子核)with DNA from a differentiated body cell. This Dolly method, known as somatic cell nuclear transfer(SCNT), can create more clones and allows researchers greater control over the edits they make to the DNA.

    Success came from adopting several new techniques. These included a new type of microscopy to better view the cells during handling or using several materials that encourage cell reprogramming, which hadn't been tried before on primates. Still, the research process proved difficult, and many attempts by the team failed. Just two healthy baby monkeys born from more than 60 tested mothers. This leads to many researchers' pouring water on the idea that the team's results bring scientists closer to cloning humans. They thought this work is not a stepping stone to establishing methods for obtaining live born human clones. Instead, this clearly remains a very foolish thing to attempt, it would be far too inefficient, far too unsafe, and it is also pointless.

    But the scientists involved emphasize that this is not their goal. There is now no barrier for cloning primate species, thus cloning humans is closer to reality. However, their research purpose is entirely for producing non-human primate models for human diseases; they absolutely have no intention, and society will not permit this work to be extended to humans. Despite limitations, they treat this breakthrough a novel model system for scientists studying human biology and disease.

    E-Sports, short for electronic sports, is one of the growing industries in the world, with prizes totaling around $25 million up for grabs in some tournaments. E-Sports are professional multiplayer video game competitions. Any video game with a strong competitive element is considered e-Sports. The competition models itself after traditional professional sports in several ways: it uses corresponding tournament formats, involves player contracts, and is governed by regulations. The athletes who compete in e-Sports competitions are gamers．

    The history of e-Sports dates back to 1972 when some Stanford University students competed in the Intergalactic Space War Olympics for the opportunity to win a one-year subscription to the Rolling Stone Magazine. E-Sports pretty much continued on the rather quiet path until the 80s when competitions like the Space Invaders Championship shot them to the spotlight. 2002 marked the beginning of a new era for the sport and laid the foundation for what e-Sports would become thanks to the release of the Xbox live, which brought online play to consoles. Halo Ⅱ became the first game to be shown on national television for Major League Gaming in 2004, paving the way for e-Sports to become a global phenomenon.

    Today, e-Sports are growing at a rapid pace thanks to advance in technology and the arrival of streaming services like Twitch which have exposed video game competitions to a new audience due to their extensive reach.

    To understand how much impact Twitch has made, data from gaming analyst group Newzoo show that e-Sports global audience increased 43 percent from 204 million to 292 million between 2014 and 2016. Interestingly, this coincides (一致) with Amazon's acquisition of Twitch in 2014 and its effort to make the competition a spectator sport.