As a child, Rob Stewart loved the natural world. “He loved everything in the sea, but sharks the most,” said his mother, Sandy Stewart.

Stewart spent his life studying and photographing sharks and other sea creatures, and creating films. Sadly, he died in 2017 at the age of 37 in a diving accident. The accident happened while Stewart was filming Sharkwater Extinction, which members of his crew completed after his death.

Knowing that about 25% of shark species were endangered and sharks might soon be extinct, Stewart worked hard to raise awareness of sharks and their key role in nature. Stewart believed that they should be protected against humans and other enemies. He studied how illegally shark finning has led to a great fall in the shark population.

When Stewart found out about the finning, he tried to end it. As an experienced diver and skilled cinematographer, he was able to raise awareness of the problem by filming sharks in their natural environment. His films, said Sandy Stewart, showed people “how beautiful the underwater creatures are. People would fall in love with them and work to protect them.”

As of 2013, 55 countries had banned shark finning. Stewart lived and died a hero in the pursuit of saving sharks and the sea. He is believed to have saved one-third of the world’s sharks.

Stewart’s parents hope kids will continue his story by supporting shark-friendly actions. They encourage kids to buy or ask their parents to buy shark-free products.

Another thing that young people can do is learn more about sharks. A good place to start is 2 “Shark Database,” an online resource that was created by Rob Stewart’s friends.

“It’s your generation that we want to make sure sees the world that Rob saw and does whatever you can to protect the big fish,” said Stewart’s father. “One person can make a big difference.”

The World Health Organization says that about 2. 2 billion people in the world still have trouble every day getting fresh drinking water especially in some countries in sub-Saharan Africa.

Now, the GivePower Foundation has developed what could be a solution to this problem. Since August 2018, the organization has been running a solar-powered desalination plant（太阳能海水淡化厂）in Kenya. The Solar Water Farm brings clean, drinkable water to about 35, 000 people every day.

GivePower says that its project is able to provide 20 years of access to clean water at a cost of only $ 20 per person—bringing not only huge health benefits to the people of the area, but breathing life into poor local economies（经济）.

Before setting up the plant, people in the area often had to travel for over an hour just to get clean water for themselves and their families. Most of the time, they had to bathe in dirty water, which led to countless health problems, including deadly diseases and waterborne illnesses.

The world faces an increasing danger of "water wars" because of increasing world temperatures and population growth as well as the inequitable distribution（不公平分配）of world resources. Hayes Barnard, the president of GivePower, hopes that the Solar Water Farm can help lead to a solution for the 844 million people around the world who simply have little access to clean drinking water—and especially those 300,000 children who die every year due to waterborne diseases. The organization has already given over 2,650 solar-powered energy systems to medical clinics, villages, and schools in 17 countries, and they are also now researching four additional places where they can set up new solar water farms.

I grew up in a small town in New Hampshire, and every morning, sometimes before I woke up, my dad left for work. I didn't know much about what my dad actually did all day. But one thing I did know about my dad's day was that he often spent his lunch break looking for books for me. He would often come home in the evening with a book for me in his bag. When he handed the "gift" over to me, I immediately investigated its cover, checked out the description on the back, and sometimes started reading right then.

I was not always as appreciative of those books as I should have been, especially in my younger years. One time, Dad brought home a paperback（平装书）called Bunya the Witch. I scanned the cover quickly before declaring, "Ugh! It's just another stupid farm book," and dropping it on the ground. I was rightfully reprimanded for being an ungrateful kid, and I learned that valuable lesson about not judging a book by its cover—Bunya the Witch turned out to be one of my favorites.

As I got older, my dad favored books focused on strong young female characters, like Invincible Louisa by Cornelia Meigs, Up a Road Slowly by Irene Hunt, and Homesick: My Own Story by Jean Fritz, books I remember to this day.

It's not just the books themselves that stay in my memory. It's the girl reading them, and what she felt as she read. I think back to hours spent in my childhood bedroom, reading about young women who faced lives much more difficult than mine. I learned from their courage and drew inspiration from their bravery.

To this day, I love to read. I love the excitement of opening up a new book and getting lost in whatever story the author wants to tell me. And quite often, when I've read something really wonderful, the first person I pass it along to is my dad. I figure I owe him.

Ways to Make Studying More Fun

The word "Studying" draws various responses from teenagers. Some students are eager to dive in and deal with the books.    16    Regardless of your attitude to studying, one thing is for sure—it has to be done. So why not make the process more enjoyable?

●Try hands-on learning. Consider going on a field trip to experience the topic directly. For example, if you're studying marine（海洋的）biology, you can take a trip to the aquarium（水族馆）.    17    If it's math you're trying to study, talk with a structural engineer about how they find out the load of a structure.

●    18    Getting together with a friend or a group of classmates can help you learn new study methods while still getting a few laughs. Try having a debate about the topic you're trying to learn. With a larger group, you can test each other's knowledge by making quizzes and making true or false tests.

●Break it up. Plan study breaks every hour and take part in an activity you enjoy.    19    Before you take a break, write down what you have learned during your study time and add to this list each time you take a break.

●Leave the house. Study at your favorite coffee shop or bookstore. If the weather is nice, go to a park or the beach. If you're a mover, hit the pavement（人行道）for a run and listen to a podcast（播客）that covers the topic you're studying, or grab a friend and quiz each other while you run.    20    

The brown bear was walking quietly behind the pink duck, ready to put his paws around her neck and throw her into a pot of boiling soup.

We turned the________. While I laughed quietly at the impracticality of a bear boiling water to________a duck, I lifted my head to find little Victoria sat huddled next to my am, honestly________to turn the page and find her favorite pink creature in a bear's________.

My________began to wander. I________the Thursday when Victoria ran into the reading room showing a golden certificate from her________. "Best reader," it showed. A smile came across my face as I looked into the eyes of the 7-year-old who just last year was________in first grade________her reading was quite poor.

It was the same________that had filled my face six months before, when Victoria joined the________program. After spending the first term answering a lot of questions, I________that Victoria's talkative nature and________for answers overshadow her desire to________and read. I________her energy and great curiosity and fueled it with my own enthusiasm. For every________she presented, I took her to scan the library shelves________a related book. I watched her eyes grow with excitement as I________helped her press through the stories, a journey in search of her ________.

Though I go to the library each week to be these kids'________, I come out, having been their student. They have introduced me to a side of me who I never realized existed.

The Singing Sand Mountains(鸣沙山) are situated in Dunhuang in western China. As one of the coolest natural phenomena on    41    planet, the dunes(沙丘) sound as if they are singing to you as you slide down them.    42     (locate) between the tall dunes, there is a little miracle(奇迹). This spring,    43    looks like a moon, has been there for thousands of years and has never dried up. The spring, even with the shifting sand,    44     (remain)blue year-round.

Climbing to the top of the dunes is hard work, but worth it. Rent a pair of bright-orange shoe protectors or just shake your    45    (shoe) out later as most people do. A wooden walkway is half buried in the sand so you can get a proper footing on the deep sand.

The dunes are a tourist    46     (attract), with dune cars, dune surfing, and helicopter flights. But it's not hard to hike away    47    (enjoy) the sandy scene in peace. The dunes look most attractive either in the morning    48    towards dusk.

The drive down the dunes is also    49    (surprise) as the large mountains of sand    50    (sudden) appear at the end of the road.