Coffee drink is widespread. When people argue about whether coffee is good for health, they're usually thinking of the health of the coffee drinker. Is it good for your heart? Does it increase blood pressure? Does it help you concentrate? However, coffee affects the health of the human population in other ways, too.

    Traditionally, coffee bushes were planted under the shade of taller trees. However, more and more farmers in Latin America are deforesting the land to grow full sun coffees. At first, this increases production because more coffee bushes can be planted if there aren't any trees. With increased production come increased profits.

    Unfortunately, deforesting for coffee production immediately decreases the local wildlife habitat, because native birds nest and hide from predators（捕食者）in the tall trees and migrating birds rest there.

    Furthermore, in the long term, the full-sun method also damages the ecosystem because more chemical fertilizers and pesticides（杀虫剂）are needed to grow the coffee. The fertilizers and pesticides kill insects that eat coffee plant, and then the birds eat the poisoned insects and also die. The chemicals kill or sicken other animals as well, and can even enter the water that people will eventually drink.

    Fortunately, farmers in Central and South America are beginning to grow more coffee bushes in the shade. We can support these farmers by buying coffee with such labels as "shade-grown" and "bird-friendly".

    Sure, these varieties might cost a little more. But we're paying for the health of the birds, the land, ourselves, and the planet. I think it's worth it.

    We know that our pet dogs and cats can recognize our faces, but our pet fish? A team of scientists from the UK and Australia have discovered that archer-fish(喷水鱼) can distinguish human faces!

    This marks the first time that a species of fish has shown such an ability. Such abilities have been previously shown in birds, but unlike fish, they have been proven to possess structures similar to the neocortex(大脑新皮层), the researchers added.

    "Being able to distinguish between a large number of human faces is a surprisingly difficult task," Dr Newport said, "mainly due to the fact that all human faces share the same basic features."

    During their experiments, Dr Newport and her colleagues presented archerfish with two images of human faces, and trained them to choose one by spitting jets(喷射流)of water at that picture. Next, the fish were presented with the familiar face and several that were unfamiliar, and were able to correctly pick the one that they had been trained to recognize, even when features such as head shape and color were removed from the selected pictures.

    In the first experiment, the archerfish were tasked with picking the previously learned face from a group of 44 new ones, which they did with 81 percent accuracy. In the second, the researchers decided to make things a little harder. They took the pictures and made them black and white and evened out (使平均) the head shapes. You would think that would throw the fish for a loop. But no, they were able to pick the familiar face even then—and with more accuracy: 86%!

    "Fish have a simpler brain than humans and entirely lack the section of the brain that humans use for recognizing faces. Despite this, fish may still be capable of finding the face they are trained to recognize," Dr Newport said. "The fact that archerfish can learn this task suggests that complicated brains are not necessarily needed to recognize human faces."

    The smallest kids on Earth are much smaller than you or your baby brother or sister. They're even smaller than the hairs on your head. We call them “NanoPutians”(纳米小人). Also known as NanoKids, the NanoPutians aren't real people. They are actually tiny molecules (分子) made to look a little bit like people.

    James Tour invented the NanoPutians as a way to teach kids about nanoscience, which refers to the study of things that are smaller than about 100 or 200 nanometers. “The exact size is less important than the possible applications of working with such tiny things,” Tour says, “Nanoscience is the study and development of the small so that it will affect the large.”

One of the goals of the research is to control individual atoms. Carbon, hydrogen, oxygen, and other types of atoms are the building blocks of the universe. They make up planets, rocks, people, trees, CDs — all the stuff out there. “Most things that people build come together in a top-down way”, Tour says. If you want to make a table, for instance, you cut down a big tree, make wooden boards, and hammer them together. Nature, on the other hand, builds things from the bottom up. When atoms join together they make molecules. Each molecule has a certain shape, and a molecule's structure determines what it can do. Molecules can make them come together to make a cell — or a tree.

    Tour and his co-workers turned these molecular structures into cartoon figures and made an animated(动画的) science video about the little people, set it to music and started showing it to kids in school while talking about how exciting research on small things can be.

    “Learning about the NanoKids has opened up a world of possibility for real kids who ordinarily would rather not study biology, chemistry or physics.” Tour says. When you look closely enough, the really small can be really cool.

    Sometimes just when we need the power of miracles to change our beliefs, they materialize in the places we'd least expect. They can come to us as a great change in our physical reality or as a simple coincidence in our lives. Sometimes they're big and can't be missed. Other times they're so subtle that if we aren't aware, we may miss them altogether. They can come from the lips of a stranger we suddenly and mysteriously meet at just the right instant. If we listen carefully, we'll always hear the right words, at the right time, to dazzle (目眩) us into a realization of something that we may have failed to notice only moments before.

    On a cold January afternoon in 1989, I was hiking up the trail that leads to the top of Egypt's Mt. Horeb. I'd spent the day at St. Catherine's Monastery and wanted to get to the peak by sunset to see the valley below. As I was winding up the narrow path, I'd occasionally see other hikers who were coming down from a day on the mountain. While they would generally pass with simply a nod or a greeting in another language, there was one man that day who did neither.

    I saw him coming from the last switchback on the trail that led to the backside of the mountain. As he got closer, I could see that he was dressed differently from the other hikers I'd seen. Rather than the high-tech fabrics and styles that had been the norm, this man was wearing traditional Egyptian clothing. He wore a tattered, rust-colored galabia and obviously old and thick-soled sandals that were covered in dust. What made his appearance so odd, though, was that the man didn't even appear to be Egyptian! He was a small-framed Asian man, had very little hair, and was wearing round, wire-rimmed glasses.

    As we neared one another, I was the first to speak, "Hello," I said, stopping on the trail for a moment to catch my breath. Not a sound came from the man as he walked closer. I thought that maybe he hadn't heard me or the wind had carried my voice away from him in another direction. Suddenly he stopped directly in front of me on the high side of the trail, looked up from the ground, and spoke a single sentence to me in English, "Sometimes you don't know what you have lost until you've lost it." As I took in what I had just heard, he simply stepped around me and continued his going down the trail.

    That moment in my life was a small miracle. The reason is less about what the man said and more about the timing and the context. The year was 1989, and the Cold War was drawing to a close. what the man on the trail couldn't have known is that it was during my Egyptian pilgrimage (朝圣), and specifically during my hike to the top of Moses's mountain, that I'd set the time aside to make decisions that would affect my career in the defense industry, my friends, my family, and, ultimately, my life.

    I had to ask myself what the chances were of an Asian man dressed in an Egyptian galabia coming down from the top of this historic mountain just when I was walking up, stopping before me, and offering his wisdom, seemingly from out of nowhere. My answer to my own question was easy: the odds were slim to none! In a meet that lasted less than two minutes on a mountain halfway around the world from my home, a total stranger had brought clarity and the hint of a warning, regarding the huge changes that I would make within a matter of days. In my way of thinking, that's a miracle.

    I suspect that we all experience small miracles in our lives every day. Sometimes we have the wisdom and the courage to recognize them for what they are In the moments when we don't, that's okay as well. It seems that our miracles have a way of coming back to us again and again. And each time they do, they become a little less subtle, until we can't possibly miss the message that they bring to our lives!

The key is that they're everywhere and occur every day for different reasons, in response to the different needs that we may have in the moment. Our job may be less about questioning the extraordinary things that happen in our daily lives and more about accepting the gifts they bring.

 "Mommy!"I called over my shoulder. "Grace is here!" Our neighbor, Grace, stood on our front door holding a cardboard box. 

It took Mom a few minutes to get to the front door. At forty-two, her health wasn't good. She smiled at our next-door neighbor. "Come in and have a cup of coffee." "I can't stay, Nancy," Grace answered. "I just thought you all might be able to use some of this food. We get more at those giveaways than we can use." I felt relieved that Grace couldn't stay. She was friendly enough, but she and her husband drank a lot and they were given to loud arguments late at night. Sometimes, the police had to come and break up the fights. I was a little frightened of them. Grace placed the box on the kitchen table. Mom, who was not the sentimental type, got tears in her eyes."Grace! We can't take this."

Dad wandered in from the bedroom where he had been napping. He wasn't dealing very well with the unemployment at the processing plant. "We don't accept charity," he said. "Now, Jim," said Grace, "this is no time for your pride. You have two little girls and a sick wife to think of. This isn't charity. It's one neighbor helping another." I stood a little distance from the grownups, looking into each of their faces, wondering what was going to happen next. "I thank you kindly," Dad said at last.

When she was gone, we examined the contents of the box. It wasn't what we were used to. Mom smiled and said, "This will get us through for a couple of weeks." The gesture from Grace confused me because she wasn't family, or close friends with us. Even though I didn't like most of the food in that box, I knew there was something significant about this woman's generosity. She didn't have much to give, but she gave what she had at a time when our family needed help.