 Welcome to Learning English, a daily 30-minute program from the Voice of America. I'm Ashley Thompson. And I'm Dan Novak. This program is designed for English learners. So we speak a little slower, and we use words and phrases, especially written for people learning English. Coming up on the program, Ashley and John Russell report on a new study that found small plastic pieces in drinking water. Gregory Stockle has a story on high inflation in Argentina, and Brian Lin has the technology report on hypersonic weapons. Later, Andrew Smith and Jill Robbins present the lesson of the day, but first... The average liter of bottled water has nearly a quarter million invisible pieces of very small plastic, known as nanoplastics, a recent study says. Researchers found the nanoplastics with a microscope using dual lasers. Scientists long figured there were lots of these very small plastic pieces. But until researchers at Columbia and Rutgers universities did their calculations, they never knew how many or what kind. Looking at five samples each of three common bottled water brands, researchers found particle levels ranged from 110,000 to 400,000 per liter. The average was around 240,000, the study said. The research appeared recently in the publication Proceedings of the National Academy of Sciences. Nanoparticles are particles that are less than a micron in size. In comparison, a human hair is about 83 microns wide. Previous studies have looked at slightly bigger microplastics that range from five millimeters, which could be seen by human eyes, to one micron. About ten to one hundred times more nanoplastics than microplastics were discovered in bottled water, the study found. Much of the plastic seems to be coming from the bottle and the filtration system to clean the water itself, said the study's lead writer, Naishin Qian of Columbia University. She would not name the three brands because researchers want more samples and they want to study more brands. Still, she said they were common and bought at Awalmart, a popular store in the US. The researchers still cannot answer the big question. Are those nanoplastic pieces harmful to health? That's currently under review. We don't know if it's dangerous or how dangerous, said study co-writer Phoebe Stapleton of Rutgers University. We do know that they are getting into the tissues of mammals, including people, and the current research is looking at what they're doing in the cells. The International Bottled Water Association said in a statement, there currently is both a lack of standardized measuring methods and no scientific agreement on the possible health effects of nano and microplastic particles. The statement added, therefore media reports about these particles in drinking water do nothing more than unnecessarily scare consumers. The American Chemistry Council, which represents plastics manufacturers, declined to immediately comment. The Associated Press spoke with four co-writers of the study. All of them said they would cut back on their bottled water use. Columbia chemist Wei Min said he has reduced his bottled water use by half. Stapleton said she now depends more on filtered water at home in New Jersey. But study co-writer Bei Jianyan, a Columbia environmental chemist, who increased his tap water usage, pointed out that filters themselves can be a problem by introducing plastics. There's just no when, Stapleton said. Outside experts who praised the study agreed that there is a general unease about the risks of fine plastic particles. Still, it is too early to say anything certain about the risks. The danger of the plastics themselves is still an unanswered question. For me, the additives are the most concerning. Said Jason Somarelli of Duke University in North Carolina. Somarelli was not part of the research. Somarelli said his own research has found more than 100 known cancer-causing chemicals in these plastics. About 15 years ago, Min invented dual laser microscope technology that identifies specific compounds by their chemical properties and how they respond when exposed to lasers. Jian and Xian talked to him about using that technique to find and identify plastics that had been too small for researchers using established methods. Carl Lavender of Law of the Sea Education Association said the work can be an important advance in the detection of nanoplastics. But she said she'd like to see other chemists use the technique and get the same results. Jian said he is starting to study water supplies in the U.S. cities of Boston, St. Louis, Los Angeles, and elsewhere to see how much plastics are in their tap water. Previous studies looking for microplastics and some early tests suggest there may be less nanoplastic in tap water than in bottled water. I'm John Russell. And I'm Ashley Thompson. Argentina's yearly inflation increased to 211.4% in 2023. Numbers released recently by the government show. It is the highest rate in 32 years. The data from the National Institute of Statistics and Sensuses, called INDEC, shows the effects of strong and difficult economic measures. They include a 50% devaluation of the country's money by President Javier Millay in hopes of bringing the country's high inflation under control. The yearly inflation number was much higher than the 95% number in 2022. For December, the monthly inflation rate was at 25.5%, up from 12.8% in November. But it is under the 30% the government had predicted. Millay said before the numbers were released that if the monthly inflation rate came in below the prediction, that would be a success. If the number is closer to 25%, it means that the success was tremendous, Millay said. In his inauguration speech, Millay announced a painful plan meant to avoid extremely high inflation. He warned that the measures would at first have harmful effects on the level of activity, employment, real wages, and the number of poor and indigent people. It is estimated that around 40% of the country's population lives in poverty. Food and non-alcoholic drinks, which have the largest effect on the yearly inflation rate, saw an average increase of 29.7% in December, INDEC found. Other products used by the general population rose by around 30%, while medications had an average increase of 40%. I'm Gregory Stockle. North Korea announced earlier this week it had carried out a test of a hypersonic weapon attached to a missile. It was not the first time the country has claimed to carry out such a test. North Korean officials announced the first one in 2021. Several other nations have confirmed they are also developing and testing hypersonic weapons. What are these weapons and which countries have them? A hypersonic weapon is designed to fly at super-fast speeds equal to at least five times the speed of sound, known as Mach 5. This is about 6,200 km per hour. These weapons are similar to ballistic missiles, which can also reach hypersonic speeds. But the difference with hypersonic weapons is that they are highly maneuverable. This means they are easy to direct and control in flight. Ballistic missiles generally have set paths with very little maneuverability. Since the path or trajectory of hypersonic weapons can be changed, they are harder to identify. This means they are difficult to destroy with existing missile defense systems. The two main kinds of hypersonic weapons are hypersonic glide vehicles and hypersonic cruise missiles. Hypersonic glide vehicles launch from a rocket. The glide vehicle then separates from the rocket and glides at speeds of at least Mach 5 toward a target. Hypersonic cruise missiles do not have a glide vehicle and are powered by high-speed air-breathing engines. Hypersonic missiles generally launch warheads at speeds of at least Mach 5 while traveling at fairly low altitudes. Newly developed hypersonic weapons fly higher than less speedy missiles, but lower than intercontinental ballistic missiles. Hypersonic weapons are more difficult to identify and shoot down. North Korea's first hypersonic missile test carried out in 2021 used a glider-shaped warhead. Another launch in 2022 involved what South Korean military officials said was a kind of ballistic missile warhead with maneuverability to hit a target. North Korean state media said the country's latest launch came on January 14. It aimed to test the performance of a new multi-stage solid fuel engine attached to a hypersonic warhead. North Korea described the test as a success. South Korean military officials said the missile flew about 1,000 kilometers before landing in waters between the Korean Peninsula and Japan. International experts have said North Korea is interested in hypersonic technology because it can be used to distantly deploy weapons while avoiding missile defense systems. North Korea could, for example, use such weapons to target U.S. military bases in Japan and Guam. The United States, Russia, and China are all developing hypersonic weapons. Additional nations are carrying out research while others have claimed tests that have not been confirmed. U.S. military and intelligence officials say China is building and testing both hypersonic cruise missiles and hypersonic glide vehicles. U.S. officials say China is believed to have carried out hundreds of hypersonic weapons tests between 2016 and 2021. Reuters reported on one Chinese test in 2021. A hypersonic glide vehicle flew through space and circled the world before heading down toward its target, the news agency said. Also in 2021, Russia successfully tested a hypersonic cruise missile. President Vladimir Putin described the launch as the start of a new generation of missile systems. The United States confirmed in September 2021 it had tested an air-breathing hypersonic weapon. The next year, the U.S. military requested $3.8 billion to develop hypersonic weapons plus another $246.9 million for hypersonic defense research. U.S. hypersonic weapons can be armed with additional warheads. The Congressional Research Service describes the U.S. Army's long-range hypersonic weapon as a ground-launched missile equipped with a hypersonic glide body and associated transport, support, and fire control equipment. The Army says such weapons are designed to reach the top of Earth's atmosphere and remain just out of reach of missile defense systems. I'm Brian Lin. Brian Lin is here now to talk more about his technology report. Thanks for being here, Brian. Sure, Dan. Thank you for having me. This week, your report took a closer look at hypersonic weapons. You've explored what they are and which countries are currently developing the technology. What are some of the main concerns being expressed about these kinds of weapons becoming more and more common around the world? So, it was explained in the report that one big advantage of using hypersonic weapons is not just their speed. Something that makes them truly unusual is their ability to be maneuvered in flight to quickly change directions. So, as many experts have pointed out, because of this unpredictability, hypersonic weapons can often escape identification by missile defense systems. Is this situation expected to change so that existing defense systems will be able to detect hypersonic weapons? Yes. So, as mentioned, hypersonic weapons can essentially trick existing missile defense methods by quickly changing course in flight. And this can make it difficult for those systems to find, lock onto, and then destroy the weapons. But some experts of the technology have said this could change in the future. It would take new detection methods, though. So, some existing ground-based radar systems can, for example, detect hypersonic weapons. But these systems are not yet equipped to give advance warning of a missile attack, so that would have to be changed. Great. Thanks again for being here, Brian. You're welcome. Thank you, Dan. Welcome to the Lesson of the Day on the Learning English Podcast. My name is Andrew Smith. And my name is Jill Robbins. Thanks for joining us. Today's lesson will help you learn more about the English you hear in our video series Let's Learn English. The series shows Anna Matteo in her work and life in Washington, D.C. Here's Anna introducing herself. Hello. My name is Anna Matteo. In our previous Lesson of the Day, we heard Anna and her friend Bruna talk about hopes and wishes. In today's podcast lesson, we're going to give you more ways to practice using the verb wish. But first, let's listen to Anna and Bruna again. This is from Lesson 10 of Level 2 of the Let's Learn English series. Hi, Anna. Hi, Bruna. What's up? I thought we could meet for lunch today. I wish I could, but I can't. I have to research Peru for a story. How's it going? Not so good. I've been reading about Peru and listening to Peruvian music. I really want to understand Peru. I hope it's enough. We wish for things we can't do, have, or be. That means we wish for things that are different from how things are now. To show this difference, English changes the form of the verb or modal that follows the word wish. For example, can changes to could, have changes to had, is, was changes to had been, and so on. So it sounds like this. I wish I could. I wish I had. I wish I were. I wish I had been. Of course, those are not complete sentences. So now we'll explain how you can practice making sentences with the word wish. First, write or think of a sentence that describes a real situation in the present or in the past. Then use a sentence with wish to express the idea that we want a different situation. Jill and I are going to give you some examples. First, we say one thing, and then we wish that thing were different. Are you ready, Jill? Ready. I can't swim. I wish I could swim. I don't understand the question. I wish I understood the question. My head hurts. I wish my head didn't hurt. Okay, notice that after the word wish, we use a word that sounds like we are talking about the past, but we are not talking about the past. Listen again to this example. I don't understand the question. I wish I understood the question. The verb understand changes to understood, but we're not talking about the past. In fact, we want to understand the question now, but because wish means that it is not possible at the present time for us to understand, we change the verb to understood. We could also say, I wish I could understand the question. This change of the verb form also happens in conditional statements, like sentences that start with the word if. Right. For example, we say, if I had more time, I would study more. The verb had does not mean the past. Instead, it shows a situation that is not real, because it comes after the word if. Okay, now let's give more examples with wish. Are you ready again, Jill? Ready. I didn't see the game. I wish I had seen the game. He is not here. I wish he were here. I smoke cigarettes. I wish you didn't smoke cigarettes. They talk really fast. I wish they didn't talk so fast. You were not at the party. I wish you had been at the party. Notice that for real statements about what people do, we change it to negative when we use wish. They talk really fast. I wish they didn't talk so fast. In the same way, the negation, shown by the word not, disappears when we use wish. I didn't see the game. I wish I had seen the game. Now it's your turn, listeners. We will say a sentence about a real situation and then give you time to say a sentence using the word wish. After you will hear us say a sentence using the word wish so you can compare your answer. Are you ready? Okay, here we go. Well, sentence number one. I can't visit my family. I wish I could visit my family. Sentence number two. I don't have a car. I wish I had a car. Sentence number three. He is always late. I wish he weren't always late. Sentence number four. They are not here. I wish they were here. Sentence number five. I didn't go to the beach. I wish I had gone to the beach. Sentence number six. She didn't help me. I wish she had helped me. Sentence number seven. She never talks to me. I wish she would talk to me. Sentence number eight. I don't know how to swim. I wish I knew how to swim. Listeners, how well did you do? Was it easy or difficult to change the sentences and use the word wish? There are a lot of forms to learn, so don't worry if you could not change all the sentences. But you can always go back and play the examples again and try to say the sentences with the word wish. We hope these exercises will be helpful. Now, before we finish, here's a little chant with more examples using the word wish. Ready? Listen. I can't sing, but I wish I could. And you don't dance, but I wish you would. You don't cook and you don't try. I wish you would cook and I wish you would try. I would if I could, but I don't have the time. I wish we had a much longer day. I do too, but what else can we say? How about this? We wish we had more time with you. We wish we did. You know it's true. But it looks like time is running out, so one more thing before we go. We hope you'll write us and let us know. Something that you wish that we would do to help you learn and have fun too. Well, we really do have to go now. Write to us and tell us your wishes at LearningEnglish at voanews.com. And remember, you can also find us on YouTube and Instagram and Facebook. I'm Jill Robbins. Thanks for listening. I'm Andrew Smith. And that's our program for today. Join us again tomorrow to keep learning English through stories around the world. I'm Ashley Thompson. And I'm Dan Novak.