Nowadays people are putting our water supply in danger, because they use too much water or throw rubbish into the river. You may wonder how paving(铺砌) a road can lead to less usable fresh water. A major part of thewaterweuse every day is groundwater. Groundwater does not come from lakes or rivers. It comes from underground. The more roads and parking lots we pave，the less water can flow into the ground to become groundwater.

    Human activity is not responsible for all water shortages(短缺). Drier climates are of course more likely to have droughts(干旱) than areas with morerainfall，but in any case, good management can help to make sure there is enough water to meet our basic needs.

    Thinking about the way we use water every day can make a big difference，too. In the United States，a family of four can use 1.5 tons of water a day! This shows how much we depend on water to live，but there's a lot we can do to lower the number.

    You can take steps to save water in your home. To start with，use the same glass for your drinking water all day. Wash it only once a day. Run your dishwasher (洗碗机)only when it is full. Help your parents fix any leaks in your home. You can even help to keep our water supply clean by recycling batteries instead of throwing them away.

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    John is a mechanic, but he lost his job a few months ago. He has good heart, but always feared applying for a new job.

    One day, he gathered up all his strength and decided to attend a job interview. His appointment was at 10 am and it was already 8:30. While waiting for a bus to the office where he was supposed to be interviewed, he saw an elderly man wildly kicking the tyre(轮胎) of his car. Obviously there was something wrong with the car. John immediately went up to lend him a hand. When John finished working on the car, the old man asked him how much he should pay for the service. John said there was no need to pay him; he just helped someone in need, and he had to rush for an interview. Then the old man said, "Well, I could take you to the office for your interview. It's the least I could do. Please. I insist." John agreed.

    Upon arrival, John found a long line of applications waiting to be interviewed. John still had some grease(油脂) on him after the car repair, but he did not have much time to wash it off or have a change of shirt. One by one, the applicants left the interviewer's office with disappointed look on their faces. Finally his name was called. The interviewer was sitting on a large chair facing the office window. Rocking the chair back and forth, he asked, "Do you really need to be interviewed?" John's heart sank. "With the way I look now, how could I possibly pass this interview?" he thought to himself.

    Then the interviewer turned the chair and to John's surprise, it was the old man he helped earlier in the morning. It turned out he was the General Manager of the company.

    "Sorry I had to keep you waiting, but I was pretty sure I made the right decision to have you as part of our workforce before you even stepped into the office. I just know you'd be a trustworthy worker. Congratulations!" John sat down and they shared a cup of well-deserved coffee as he landed himself a new job.

    You know the feeling—you have left your phone at home and feel anxious, as if you have lost your connection to the world. "Nomophobia(无手机恐惧感)" affects teenagers and adults alike. You can even do an online test to see if you have it. Last week, researchers from Hong Kong warned that nomophobia is infecting everyone. Their study found that people who use their phones to store, share and access personal memories suffer most. When users were asked to describe how they felt about their phones, words such as "hurt" (neck pain was often reported) and "alone" predicted higher levels of nomophobia.

    "The findings of our study suggest that users regard smartphones as their extended selves and get attached to the devices," said Dr Kim Ki Joon. "People experience feelings of anxiety and unpleasantness when separated from their phones." Meanwhile, an American study shows that smartphones separation can lead to an increase in heart rate and blood pressure.

    So can being without your phone really give you separation anxiety? Professor Mark Griffiths, psychologist and director of the International Gaming Research Unit at Nottingham Trent University, says it is what is on the phone that counts—the social networking that creates Fomo (fear of missing out).

    "We are talking about an Internet-connected device that allows people to deal with lots of aspects of their lives," says Griffiths. "You would have to surgically remove a phone from a teenager because their whole life is ingrained in this device."

    Griffiths thinks attachment theory, where we develop emotional dependency on the phone because it holds details of our lives, is a small part of nomophobia. For "screenagers", it is Fomo that creates the most separation anxiety. If they can't see what's happening on Snapchat or Instagram, they become panic-stricken about not knowing what's going on socially. "But they adapt very quickly if you take them on holiday and there's no Internet," says Griffiths.

    In this Pennsylvania city, Pittsburgh is shrinking but getting wealthier. Since 2000, its population has declined by 95,000 while its income per capita (人均) has shot up 24 percent. The trend is taking hold in many other cities, like Buffalo in New York, Providence in Rhode Island and New Orleans.

    Some of these areas have created more high-paying jobs in energy, health care or education. Others have managed to reshape their manufacturing (制造业) for a new economy. Higher-paying jobs have a greater effect because they create demand for additional services. “The story in Pittsburgh is very positive, and other areas are looking at it as an example of the transformation that might be possible,” said Guhan Venkatu, who wrote an economic history of the area called “Rust and Renewal” for the Federal Reserve Bank of Cleveland.

    Carnegie Mellon University and the University of Pittsburgh have helped bring tech jobs and innovation (革新) to the area by sponsoring tech centers that help graduates start companies without moving to Silicon Valley or San Francisco. This has helped keep Pittsburgh's educated young population growing even as the entire population in the city has dropped.

    Pittsburgh has more STEM (science, technology, engineering and math) jobs than other shrinking cities, about 80,000 or 7% of all jobs. STEM jobs add productivity and income growth to the area. Manufacturers of high-tech medical equipment in the Pittsburgh area also have doubled employment in the last 10 years.

    However, some experts question whether growing income per capita can really make up for a declining population. According to Patrick Adler, a researcher at the University of Toronto, population loss does matter if it means lower-skilled workers have fled because of a lack of opportunity. What's more, high-paying jobs in education and health care can disappear if the population declines too greatly. So it'd be wise to find ways to increase the population.

    When I was about twelve, I headed to a restaurant for dinner with my family. It was winter, and on that night, the wind was really blowing hard.

    As my mom and I headed to the restaurant from our car, a girl about my age and her mother came up to us. They asked if we had any spare change (零钱). My mom right away asked where they lived. They pointed to an old car in a parking lot across the street. The girl said there were six of them living in that car. My mom said she had something to do after handing the people a few dollars. She sent me inside the restaurant with my dad and my three siblings (兄弟姐妹). But she didn't come. Later, I found out she had gone home and put all the food in our cupboards (食橱) into a few bags. Then, she brought that food over to the car and handed the bags to the family. I wasn't there when that happened, but I can only imagine the joy it brought to those people.

    A few days later, when I actually found out about what she had done, I asked her why she helped those people. She told me that they were not lucky. I remember the face of that girl who had asked us for change. She was the same age as me, yet we looked so different.

    Here I stood, dressed in almost new clothes, headed to eat in a restaurant and then back home to the bedroom I shared with my younger sister. I remember thinking that the other girl didn't have any food to eat and she was heading back to a cold car shared with five other people.

    After painting this picture in my mind, I understood why my mom had done what she did. I will never forget what she did that night, and how she taught me one of the best lessons I ever learned.

When it comes to lowering blood pressure,studies have typically shown that aerobic(有氧的)exercises are best. Recent research suggests another type of physical activity is worth including as an effective tool to prevent and treat high blood pressure.

Exercises that engage muscles without movement,such as wall squats and planks,may be best for lowering blood pressure,according to a large study published in July,2023 in the British Journal of Sports Medicine.

This type of training is known as isometric exercise,according to the Mayo Clinic.Isometric muscle action happens when muscles contract but do not visibly change length,and the joints involved don't move,facilitating stability of the body.Isometric exercises can be done with weights or without,just relying on the body's own weight.

"These findings provide a comprehensive data-driven framework to support the development of new exercise guideline recommendations for the prevention and treatment of high blood pressure,"said study coauthor Dr.Jamie O'Driscoll in a news release.  The researchers looked into randomized controlled trials that had reported the effects of exercise interventions, lasting two or more weeks,on blood pressure between 1990 and February 2023.From a review of 270 trials with 15,827 participants,the researchers  found that  among HIIT  (high  intensity interval training),isometric  exercise, aerobic exercise,dynamic resistance training and a combination of the latter two,isometric exercise led to the greatest reductions in blood pressure.

It's also important to note that there are other lifestyle changes as well as exercise that can benefit your blood pressure.These include keeping to a healthy weight,eating a balanced diet,cutting down on salt,not drinking too much alcohol and ensuring that you continue to take any prescribed medication.

More research is needed to determine exactly why isometric exercises might be better for lowering blood pressure than other types of training,the authors said.