I call my story the story of a bad boy, partly to distinguish myself from those faultless young gentlemen, and partly because I really was not an angel. I may truthfully say I was a friendly, impulsive(易冲动的)teenager. I didn't want to be an angel. In short, I was a real human boy, such as you may meet anywhere in New England.

Whenever a new scholar came to our school, I used to ask him "My name's Tom Bailey; what's your name?" If the name struck me favorably, I shook hands with the new pupil cordially, but if it didn't, I would turn and walk away, for I was particular on this point.

I was born in Rivermouth almost fifty years ago, but, before I became very well acquainted with that pretty New England town, my parents moved to New Orleans. I was only eighteen months old at the time of the move, and it didn't make much difference to me where I was, because several years later, when my father proposed to take me North to be educated, I had my own view on the subject. I instantly kicked over the little boy, Sam, who happened to be standing by me at the moment, and declared that I would not be taken away to live among a lot of Yankees! You see I was what is called "a Northern man with Southern principles," I had no recollection of New England: my earliest memories were connected with the South. I knew I was born in the North, but hoped nobody would find it out. I never told my schoolmates I was a Yankee, because they talked about Yankees in a scornful way which made me feel that it was quite a shame not to be born in the South.

And this impression was strengthened by Aunt Chloe, who said, "There wasn't no gentlemen in the North no way."

    With this picture of Northern civilization in my eye, the readers will easily understand my terror at the bare thought of being transported to Rivermouth to school, and possibly will forgive me for kicking over little Sam, when my father announced this to me. As for kicking little Sam, I always did that, more or less gently, when anything went wrong with me.

    My father was greatly troubled by this violent behavior. As little Sam picked himself up, my father took my hand in his and led me thoughtfully to the library. He appeared strangely puzzled on learning the nature of my objections to going North.

"Who on earth, Tom, has filled your brain with those silly stories?" asked my father calmly.

"Aunt Chloe, sir, she told me."

My father devoted that evening and several evenings to giving me a clear account of New England: its early struggles, its progress, and its present condition. I was no longer unwilling to go North; on the contrary, the proposed journey to a new world full of wonders kept me awake nights. Long before the moving day arrived I was eager to be off. My impatience was increased by the fact that my father had purchased for me a fine little Mustang pony, and shipped it to Rivermouth two weeks before the date set for our own journey. The pony completely resigned me to the situation. The pony's name was Gitana, which is the Spanish for "gypsy", so I always called her Gypsy.

    Finally the time came to leave the vine-covered mansion among the orange-trees, to say goodbye to little Sam(I am convinced he was heartily glad to get rid of me), and to part with Aunt Chloe. I imagine them standing by the open garden gate; the tears are rolling down Aunt Chloe's cheeks; they and the old home fade away. I am never to see them again!

    Recently I had a conversation in Beijing with an adult Chinese friend who was complaining how difficult it was to study English. No surprises there. It is a difficult language to master, just like Chinese. I made a few suggestions based on my experience. One involved a very valuable fact which I learned from my high school Latin and Greek teacher, Dr. Smith．He is a gifted linguist （语言学家），and has an amazing ability to remember things, like poetry, essays, speeches, etc．His advice to us students is that for memorization purposes, there is forty minutes each day in which our memory is more acceptable than it is during the other 23 hours and 20 minutes.

    This 40-minute "super memory" period is divided into two parts: the 20 minutes before we sleep, and the 20 minutes after we first awake. The theory supporting this is pretty simple. First, the last information we input into our brain before bed has a better chance of taking root than information gained during the noisy daytime; and second, our mind is free of disturbance(干扰) when we first awake in the morning一so more receptive to inputs, like a blank slate（石板）．

    I took the advice to heart and it served me well in my school years. In my university days, our Chinese teacher would assign us 200 new vocabulary words each day, on which we would be quizzed（测试）the following day. Without the "magic" 40-minute technique, there's no way I would have passed those daily quizzes.

    As far as language study goes, it's not only useful for memorizing vocabulary. It's also a very useful window of time to listen to the language we're studying even with background noise, and even if it's at a level we find difficult to understand. It might be audio（声音的）language study, aids, or just radio, TV or whatever.

    Beyond our years of formal(正式的) education, memory skills are hugely important in any career. How many times have we heard a speaker read their speech from a prepared text, or read the word-by-word content of a PowerPoint presentation as they present each slide（投影片）? These are annoying, boring, and less effective ways of communicating. They are almost guaranteed(保证) to lose the audience's close attention and interest, let alone persuade or inspire anyone to do anything. And yet lots of people still make this mistake.

    If we use the 40-minute technique, we may not succeed in memorizing our presentation content on a 100% word-by-word basis, but we'll be familiar enough so that we can spend much more time making eye contact with our audience. We will get them in the process, while looking at our text instead of staring at it. This will also free up our hands and arms to convey some extra messages through gesture．

    As you see, the technique really works, but like many things, it takes practice to perfect it. Therefore, we'd better find ways to use the language outside of the classroom, as regularly and frequently as possible. One basic rule of language learning is, "Use it, or lose it·”

Seize the forty-minute learning window and we'll bring in a rich harvest of language learning.

    When her classmates were having a good time, Molly sat at the picnic table alone. She remained awkward around her classmates. She seemed unsure of what to do or say, yet I could see her eyes longing for acceptance. Many students had already decided that her friendship would not be worth the energy required to overcome the awkwardness. Others teased her. Most ignored her except for one.

    Brianna, the class clown, was making the other students laugh, as usual. “Brianna, do you see Molly down there? Would you mind walking down there and inviting her to come up here with the rest of us?”

    Brianna sighed. I could tell she didn't want to sacrifice precious minutes of her own recess (休息) to do what I was asking of her, but I also knew her heart. She often thought of others before herself— a rare character for anyone, much less a kid.

    Knowing this choice was hard for her, I reached into my pocket and pulled out a D-buck, our class currency. Though bribery (行贿) was not the ideal way to handle this situation, I needed her cooperation.

    “Here, I'll pay you for your time.”

    She offered an insincere smile, grasped the green paper, and headed down the hill.

    As the rest of the children screamed and laughed, my eyes locked on Brianna as she neared the picnic table. Molly could be difficult, and I wouldn't have been surprised if she sent Brianna back alone, refusing her invitation. When she encouraged herself to a standing position, I sighed with relief.

    A minute later, I felt a tap on my shoulder. “Here, Mrs. D.” She handed me the D-buck.

    “Why?” I asked.

    “I shouldn't keep this,” Her eyes fell to her feet, guilt radiating from her quiet voice. “I don't want Molly to think I only went to get her so I could earn a D-buck. She's my friend.”

    A moment later, they were all laughing again, and who should I see among them, laughing for the first time that week? Molly.

    In the middle of the 19th century，a fever dream of riches beyond measure drew countless explorers west to the mountains of central California. Although the gold rush ended up being a bust for many who sought a fortune，some of those explorers discovered a natural treasure that would draw permanent settlers to Yosemite Valley in the following decade.

    Vast wilderness，beautiful mountains，countless waterfalls，and abundant wildlife drew Native Americans to Yosemite roughly 10，000 years ago. The first non-native tourists arrived in the mid-1850s after reports from gold seekers told of an area of breathtaking beauty that no words were able to describe.

    Fortunately，some of Yosemite's earliest settlers recognized that Yosemite's natural beauty and resources needed to be preserved for future generations. In the midst of the Civil War，President Abraham Lincoln signed a grant to protect Yosemite permanently，thus making it the nation's first land to be dedicated to recreation and setting the stage for what would become the national park system.

    One of Yosemite's earliest ambassadors was Scottish-American naturalist and writer John Muir. After living in Yosemite for a few years，he helped define its proposed boundaries. He also wrote articles that helped lead to its official title as a National Park in 1890.He later co-founded the Sierra Club in 1892 to advocate for its continued preservation and protection.

    Located on the western slope of the Sierra Nevada mountain range in central California，Yosemite National Park runs across nearly 748，000 acres，almost 95％of which is wilderness. Around four million visitors come to Yosemite each year to camp，hike its miles of trails，climb its rock formations，and photograph its impressive sights. Are you ready to visit Yosemite National Park? Which of Yosemite's sights would you most like to experience?

    Human began farming around 12,000 years ago, and only in the past 50 years have scientists realized we're not the only species to research into agriculture. A new study has revealed that a small Fijian ant species beat us to becoming the first farmers by almost three millions years.

    The ants have been observed carefully sowing seeds, fertilizing (施肥) them, and waiting for them to grow into plants which bear tasty fruit. What led to the formation of this relationship remains a mystery to scientists. But it puts the ants millions of years ahead of the first human societies to use farming techniques.

    The newly discovered relationship is unique to the animal kingdom. Researchers say they have already watched ants spread seeds, and ants feed plants, but they never had a case where they farm a plant they can't live without. The ants rely on the plants for shelter and food, while the plants need the ants to sow and spread their seeds.

    The find puts the ants millions of years ahead of the first human societies to use farming techniques, who began using agriculture around 12,000 years ago.

    As the plants grow under the care of the ants, the plants to keep further growth. Once the plant is big enough, its hollow chambers provide shelter for the ants. It had previously been spotted that the ants like to live in these small chambers, but the Munich researchers have uncovered the true nature of the relationship that ants sow and take care of the plants to grow themselves a new home.

    The ants will eat the fruit of the plant and harvest their seeds for further projects.

While many other examples of mutually (相互地) beneficial relationships between ants and plants exist, the discovery marks the only case in which both parties other for are totally dependent on each other survival.

The outbreak of locusts, an insect that mainly lives in Africa and Asia, is the worst experienced by Kenya in 70 years. The crowds are some three times the size of New York City, eating their way through thousands of acres of crops and animal grassland and destroying livelihoods in the process.

"These hungry things are alarming," says Keith Cressman, the UN Food and Agriculture Organization's senior locust forecasting officer. "A crowd the size of Manhattan can, in a single day, eat the same amount of food as everyone in New York and California combined."

Desert locusts are infamous for their ability to breed(繁育)rapidly in large numbers every three months. And with some help from the wind, they can travel as much as 80 miles a day. Most years, the insects stay in African deserts. However, under the right environmental conditions, they can multiply quickly, spread as much as 400 times every six months and cause extensive destruction if left unchecked.

"The insect has the ability to take advantage of good conditions." Cressman says.

The "good conditions" the scientist is referring to began in mid-2018 when a rainstorm from the Indian Ocean struck a remote area of the Arabian Peninsula known as the "Empty Quarter". Normally, it would dry out within a short period, killing most of the locust population, which depends on green plants for food. However, in late 2018, a second rainstorm struck the same region. The huge sandy area got wet, which is exactly what desert locusts need to lay their eggs and breed. The extra food supply caused the population to explode for the second time in six months.

Luckily, the locusts, experts say, are easy to control with chemicals. Kenya badly needs equipment and a steady supply of chemicals to effectively wipe out the massive insects. Hopefully, leaders worldwide will recognize the tough situation and contribute generously to control the locust outbreak.