Two of the saddest words in the English language are “if only”. I live my life with the goal of never having to say those words, because they convey regret, lost opportunities, mistakes, and disappointment.

    My father is famous in our family for saying, “Take the extra minute to do it right.” I always try to live by the “extra minute” rule. When my children were young and likely to cause accidents, I always thought about what I could do to avoid an “if only” moment, whether it was something minor like moving a cup full of hot coffee away from the edge of a counter, or something that required a little more work such as taping padding (衬垫) onto the sharp corners of a glass coffee table.

    I don't only avoid those “if only” moments when it comes to safety. It's equally important to avoid “if only” in our personal relationships. We all know people who lost a loved one and regretted that they had foregone an opportunity to say “I love you” or “I forgive you.” When my father announced he was going to the eye doctor across from my office on Good Friday, I told him that it was a holiday for my company and I wouldn't be here. But then I thought about the fact that he's 84 years old and I realized that I shouldn't give up an opportunity to see him. I called him and told him I had decided to go to work on my day off after all.

    I know there will still be occasions when I have to say “if only” about something, but my life is definitely better because of my policy of doing everything possible to avoid that eventuality. And even though it takes an extra minute to do something right, or it occasionally takes an hour or two in my busy schedule to make a personal connection, I know that I'm doing the right thing. I'm buying myself peace of mind and that's the best kind of insurance for my emotional well-being.

    Researchers at Stanford University have developed a new material that can move heat out of buildings and into space. The researchers say the material can cool buildings even on hot days. The cooling material is a very thin sheet with many layers that could be placed on a roof like solar panels(板). However, instead of turning sunlight into energy as solar panels do, the material turns heat into infrared（红外线的）radiation.

    Shanhui Fan is an electrical engineering professor at Stanford University. He says that the panels have a layer of material that is like sand. The panels act like a mirror. They take heat out of buildings and reflect the light from the sun. And he says both the heat and sunlight arc sent 100 kilometers into outer space. "It's a structure that cools itself without electricity input, even under the sun. So, what it does is basically radiate heat to outer space and also reflect the sunlight so it doesn't get heated up by the sun. Mr. Fan says it is like having a window into space. The heat is sent directly into space without increasing the air temperature

    He says buildings in developing countries that do not have electricity or air conditioning could use the panels. "In areas where electricity is out of reach for many people, there is a potential benefit for storing medicine or even food. In many of these situations, being able to reduce the temperature is important. And this would provide a way to do it.”

    The researchers say the main problem is creating actual cooling systems using the high-tech panels. They say it may be possible to develop a cooling spray(喷涂）that could be used on present solid structures. They believe the cooling spray technology could be developed in the next three to five years. They say as much as 15 percent of the energy used in the United States is spent providing power to air conditioning systems.

    I'm a reporter. Last month I was in Stockholm, Sweden. Now I'm in Frankfurt, Germany. Next month, who knows?

    You certainly won't believe that I can call you from my laptop, which is what I'm often doing these days using something called Skype.

    Skype lets me call any phone number anywhere in the world for about 2 cents a minute, a little more to some places, such as the Middle East and Asia. My computer does the dialing, and the processing of incoming and outgoing voices. All you need is a broadband connection (宽带接头). With the basic version of Skype, all anyone needs to make or receive a call is to install the program on his or her computer (and that includes personal digital assistants). All calls from PC to PC are free.

    You don't even need a pair of headphones, though headphones can be a good idea if you wish to be discreet. I use my laptop's built-in microphone.

    The paid service for calling regular telephones is called SkypeOut. The quality is completely clear, provided that there's not too much traffic on the Internet. If there's an echo, hang up and try again, and it usually gets better. There is one warning: on some computers, especially those running older versions of Windows, it doesn't always work, or can sound like a confusing conversation. You can't hear a thing.

    Skype was invented chiefly by a Swede named Niklas Zennstrom along with a group of programmers in Estonia.

    After I mastered my first concerto (协奏曲) at the age of 14, my parents decided to get me a nice violin. I tried out dozens of instruments before I found my match: a German violin. It was beautiful, but what I liked best about it was its voice. Confident and strong, it was everything I longed to be.

    I'm not sure how much that violin cost, but my parents made me promise never to let it out of my sight. They didn't understand that pulling a large violin case ran counter to my daily middle school task of not being noticed. I was a strange, absent-minded kid. When I spoke up in class, my comments brought confused silence from teachers and wild laughter from students. Like a deer in a wolf pack, I tried to be quiet and still.

    However, my new violin was almost shockingly loud. Together, we were much louder than the rest of my middle school orchestra—which was encouraged, since the other kids made sounds like cats' crying. For one wonderful hour every day, I was showered with attention. Everyone wanted to hear what I had to say.

    Between classes, I bent under the combined weight of my violin case and a backpack filled with books. My body suffered, but my confidence grew. With my violin by my side, I found my voice. More and more, I contributed to class discussions and even made a couple of friends.

    Today, I'm just an excellent violinist with a regular day job. As I sit in my community orchestra, sometimes I feel jealous (嫉妒的) of my fellow musicians' instruments with their elegant voices. I may not be the best violinist around, but at least I'm still the loudest.

Where does the meat on our table come from? It usually comes from livestock like chickens and cows. But did you know that meat can also be made in a lab? US company JUST has announced that lab-grown meat could be on some restaurant menus in the United States and Asia by the end of 2018, The Independent reported.

"These meats include chicken nuggets (鸡块), sausage and foie gras (鹅肝酱)," Josh Tetrick, CEO of JUST, told The Independent. Lab meat is sometimes referred to as "clean meat". It is made using the stem cells (干细胞) of living livestock. The cells need to be grown in a lab for a few weeks. For example, making a hamburger patty (肉饼) takes about nine weeks, CNN reported. This is faster than raising a cow, which usually takes over 20 weeks.

The first clean meat was a beef burger that was produced in 2013, but it was said to taste quite dry. How does clean meat taste now? Clean meat supporters told CNN that they think it tastes just like traditional meat.

Clean meat has other advantages. It is healthier than traditional meat. Meat producers can control what type of fat goes into the meat. They can produce clean meat that contains healthy fats, such as omega-3 fatty acids (脂肪酸). This kind of fat is good for people's hearts.

Clean meat can also help to solve global warming. According to The Washington Post, about 14.5 percent of the planet's greenhouse gas emissions (排放) come from raising livestock. That's more than the emissions from every car, train, ship and airplane in the world combined. It is predicted that switching to clean meat could lower greenhouse gas emissions by 96 percent, The Independent reported.

Pick up any packaged processed food, and there's a decent chance that one of its listed ingredients will be "natural flavour". The ingredient sounds good, particularly in contrast to "artificial flavours" since there is a common belief that ingredients from nature are necessarily safer than something artificially made. But it's not true. Then what exactly does the natural flavour mean? It refers to extracts (提取物) got from natural sources like plants, meat or seafood. When consumers see the "natural flavour" on a label, they are unlikely to assume that someone is squeezing the juice from oranges into their bottles. They know even though natural flavour must come from natural sources, it needn't all come from the plant or meat. For example, orange flavours might contain not only orange extracts, but also extracts from bark and grass.

So if flavours like orange are needed, why not just use oranges? The answer comes down to "availability, cost, and sustainability", according to flavour chemist Gary Reineccius of the University of Minnesota. "If you're going to use all your grapes on grape soda," Reineccius says, "you don't have any grapes for wine making; the products are going to be exorbitant; besides, what do you do with the by-products you create after you've squeezed all the juice out of the grapes?"

Actually, while chemists make natural flavours by extracting chemicals from natural ingredients, artificial flavours are made by creating the same chemicals artificially. The reason why companies bother to use natural flavours rather than artificial flavours is simple: marketing. "Many of these products have health titles," says Platkin, professor from Hunter College. "Consumers may be talked to believe products with natural flavours are healthier, though they are nutritionally no different from those with artificial flavours. Natural flavours may involve more forest clear-cutting and carbon emissions from transport than flavours created in the lab."

Platkin suggests getting more transparent (易懂的) labeling on packaging that describes exactly what the natural or artificial flavours are, so consumers are-not misled into buying one product over another because of "natural flavours". Reineccius also offers simple guidance: "Don't buy anything because it says ‘natural flavours'. Buy it because you like it."