2 . It’s perhaps the world’s most famous underwater attraction that remained in film and in legend: the Titanic. But now experts say the ocean liner, once a wonder of the high seas, is falling to pieces.

Capt. Alfred McLaren, the scientist who in July led the most recent expedition to the ship’s underwater grave, said his team saw clear signs of the accelerating damage of the wreck (残骸). There was damage likely caused by rust and sea life, and the captain’s cabin had collapsed.

“I was absolutely astonished,” McLaren said.

Worse still, the fallen mast (桅杆) that crushed the ship’s deck is believed by many to be the result of an unapproved salvage (打捞) operation. “It was almost depressing to see how quickly she was getting worse,” McLaren says. “I would be really surprised if there’s very much standing up from the bottom, two decades from now.”

Ed Kamuda, who runs the Titanic Historical Society in Springfield, Mass., says adventure tourists — who pay $36,000 each to visit the wreck — are also contributing to the destruction of it.

“This is something I expected. I just didn’t expect it to happen so quickly,” Kamuda said. “People are going down just as an ego trip to say ‘I was there.’ All this takes a fare on the ship.”

The Titanic has sat at the bottom of the Atlantic since it sank after hitting an iceberg on its maiden voyage on April 14, 1912. More than 1,500 people died that night. The ship came to rest at the bottom of the freezing North Atlantic, more than 2 miles beneath the waves. The wreck was discovered in 1985, and since then it has been repeatedly visited by treasure hunters.

But still some scientists say those divers, and other thrill seekers are not necessarily to blame for the Titanic’s current problems.

Capt. Craig McLean of the National Oceanic and Atmospheric Administration went on an expedition to the Titanic in June as part of a government study that is monitoring the condition of the ship. He says it’s unclear what part of the damage is from Mother Nature and which is from human nature.

“It’s too early and there isn’t enough evidence to put our fingers on anything,” McLean said.

Regardless, most agree there’s little that can be done for this most famous of wrecks. And soon, the mighty Titanic could well be lost again.

4 . Carried by the wind, dust particles (微粒) from places such as the Sahara Desert can float halfway around the world before settling to the ground. As the plastics abandoned by humans break down into tiny pieces in the environment, they, too, travel through the atmosphere. Now scientists are a step closer to understanding how these microplastics travel in the globe — both locally and on long-distance flights.

Researchers spent more than a year collecting microplastics from 11 national parks and wilderness areas in the western U.S. They examined the particles that settled on dry days and those that fell along with rain or snow. In addition to making clear how microplastics move around, the results, published on Thursday in Science, reveal the seriousness of the problem: more than 1 million kilograms of microplastics — the weight of 120 million to 300 million plastic water bottles — fall on protected lands in the country’s western region each year.

The new findings add to scientists’ concern over microplastic pollution’s potential impacts on the environment and human health. “We’re not supposed to breathe in this material,” says Steve Allen, a microplastics researcher at the University of Strathclyde in Scotland, who was not involved in the new study. “Plastics in the environment “carry all sorts of pesticides (农药), heavy metals and all the other chemicals that we’ve made over time,” he adds. “They’re going to carry them directly into our lungs.”

Since their discovery in oceans in the 1970s, microplastics — which can be as large as a grain of rice or smaller than a particle of dust — have been found nearly everywhere researchers have looked: in cities, in Arctic snow, on remote mountaintops. Their presence in areas distant from the place where human live has pointed to them being carried by winds.

5 . A baby born before 28 weeks isn’t likely to survive. However, born at the 23rd week, Grandpa made it with the help of diligent doctors and _________ nurses. Without them, I probably wouldn’t be here.

Right after Grandpa was born, the doctors _________ him to Children’s Hospital. They were so _________ as if they were flying! When they got to the _________, doctors and nurses put Grandpa in one incubator (恒温箱). After that, the doctors ran some tests. When the tests were done, people knew that Grandpa would have to live in an incubator for 5 months, until he _________ enough to survive outside. One thing that helped Grandpa _________ was pure oxygen. All those months, Grandpa’s eyes were _________ to pure oxygen directly. As a _________, the pure oxygen damaged Grandpa’s eyes. When Grandpa was 2, he was found _________.

Grandpa didn’t let his blindness stop him from living a good life. He went to college, but __________ going there a year later because of family reasons. Then, he went to Lindenwood University. Because he couldn’t __________ by himself, the state provided him with a scanner. He put the __________ of a book in front of the scanner, which would read the page to him. If Grandpa maintained good grades, the state would __________ him to keep the scanner, or it would be taken away. Grandpa __________ graduated with good grades.

It’s a(n)__________ that Grandpa survived being born 17 weeks early. Also, he didn’t let his blindness get in his way. He kept on trying everything and now lives a good life

6 . Who has no regrets about things done in the past? Wouldn’t it be nice if, somehow, we could go back to change a couple of bad decisions? This sounds like science fiction.

The laws of physics prohibit traveling back in time for many reasons. If we did travel back in time and changed the course of events, we would be altering the course of history. An example often cited is the grandfather’s paradox (悖论): If your grandfather died when he was still a high school student, he wouldn’t have met your grandmother and your father and you wouldn’t exist.

Putting humans or consciousness traveling back in time aside for the moment, is there anything in science even similar? Surprisingly, yes. At the level of quantum particles (量子粒子), there is something called Wheeler’s delayed-choice experiments that show that actions in the present can influence the past. The experiments use something called the wave-particle duality (波粒二象性) of light and of matter. The fact that the physical nature of quantum objects is undetermined until it is measured. In other words, this means that a particle of light or of matter can behave either as a wave (spreading out in space) or as a particle (staying together) depending on the measuring devices. Long and ongoing discussions about the nature of quantum physics are still trying to work out what this actually means. Do our minds determine the nature of physical reality?

Should we offer food for thought for the future or the past? Unfortunately, these experiments say very little about how we could interfere with the past in events relevant to the human scale. Better to think carefully about decisions than to try to fix them backwards.

7 . Every week, Angela looked at her recycling bin, filled with shampoo bottles and plastic containers, with mixed feelings. Sure, it was a lot of plastic, but it was going to be recycled. Or so she thought. Then, her husband sent her some articles revealing that less than 6% of the country’s plastic gets recycled. She was shocked.

Determined to cut back on her plastic consumption, Angela got a starter kit from a company selling refillable household cleaners (家用清洁器). In it were tablets, containing concentrated hand soap as well as glass and bathroom cleaners, and four empty containers. She filled each one with tap water, then dropped in a tablet and watched it dissolve. If she was happy with the cleaners, she would order more tablets but reuse the containers. No new plastic required.

Given plastic’s harmful effects on the environment, nearly three quarters of Americans say they are trying to reduce their reliance on single-use plastic, according to Pew Research Center. Since plastic is everywhere and avoiding it altogether is extraordinarily difficult, some, like Angela, have revived a once-customary practice: refilling containers. Household cleaners seem particularly prepared for a refill revolution, for many can be easily concentrated and reconstituted (with water. If just 10% to 20% of plastic packaging are reused, a report from the World Economic Forum estimates, the amount of plastic waste entering the ocean will be cut in half.

Not everyone is as enthusiastic, though. Jan Dell, a chemical engineer, noted that many cleaning products are packaged in PET or HDPE, two types of plastic with relatively high recycling rates. So she is less concerned about them but far more concerned about the packaging of other products. “What companies should be focusing on is everything else that isn’t recyclable, that is single use and that often becomes plastic pollution,” she said, pointing to plastic bags and cups. “This is just a classic example of big corporations doing something to attract people’s attention over here on something that’s not the main issue to distract from all the single-use plastic they’re pushing out.”

8 . I was born with a rare disease that prevented the normal growth of my right arm. I was heart-broken at school. Those cruel experiences won’t affect me now, but back then they struck me very hard.

My parents realised playing with Lego was a great way to improve my flexibility, so they bought me a set when I was five. I built planes and cars, and even a prosthetic (义肢的) arm, though I had already decided I didn’t need a prosthetic arm — it was very expensive, and I was doing just fine.

I made one because it’s fun. I have since made several new versions. And my latest model is the most advanced and comfortable. It has a control unit that can send and receive orders from sensors on the arm to the motors, with cables that contract like muscles.

A lot of people don’t have the ability to buy a prosthetic. I hate it when people have to pay up to €100,000 for a prosthetic. They shouldn’t pay that much — it’s not a luxury. My goal is to try to make some that more people can afford.

When I was 19, the parents of an eight-year-old boy got in touch to ask if I could build him a prosthetic. His arms and legs are underdeveloped as part of his condition, so I made two prosthetic arms using Lego units costing only €15. His smile when he used them for the first time was very encouraging.

To me, my creations don’t necessarily tell the story of how I overcame my condition with Lego; they’re about how I overcame the tough period almost every day at school.