A new study suggests lightning strikes that hit Earth after its formation may have unlocked a necessary chemical element to support the beginning of life. Researchers say the lightning may have supplied enough phosphorus (磷) to Earth during the first billion years after the planet was formed. Scientists believe life started on Earth about 3.5 to 4.5 billion years ago.
Phosphorus is an important element for the formation of life. It helps form cell structures and supports DNA, the material present in nearly all living organisms. But on early Earth, phosphorus is believed to have been first locked inside minerals that cannot dissolve in water.
Until now, it was widely believed that meteorites (陨石) that struck Earth were mainly responsible for the presence of “bioavailable” phosphorus. Some meteorites contain a phosphorus mineral called “schreibersite”, a highly reactive mineral that can form organic molecules.
But when lightning strikes the ground, it can create glassy rocks called “fulgurites” by super-heating and sometimes vaporizing rocks on the surface. This process frees the phosphorus locked inside. As a result, these “fulgurites” can contain “schreibersite”, which can be dissolved in water, where life is thought to have formed.
The researchers say levels of phosphorus minerals caused by lightning strikes were found to have been higher about 3.5 billion years ago. The researchers think this was about the age of the earliest-known fossils widely accepted to be those of microorganisms. Scientists believe the earliest bacteria-like organisms were formed in Earth’s early waters. But there is a debate over when this happened and whether it happened in warm and shallow waters or in deeper waters.
New research does not completely cancel the theory that meteorites could have been another source of life-giving phosphorus. Meteor (流星) strikes around the time of the appearance of life are far less than thought a decade ago.
1. Where did the phosphorus first exist on early Earth?| A．In meteors. | B．In lightening. | C．In minerals. | D．In water. |
| A．Life is born. | B．Phosphorus is released. |
| C．Rocks become soil. | D．Meteorites are broken. |
| A．The number of lightning strikes. |
| B．The age of the earliest-known fossils. |
| C．The time of the disappearance of life on Earth |
| D．The depth of the earliest lifeforms on Earth in water. |
| A．Life Might Have Begun from Three Sources |
| B．Life Needs an Important Substance to Get Started |
| C．Lightning May Have Helped Life Develop on Earth |
| D．Scientists Have Discovered the Earliest Meteor Strike |
相似题推荐
【推荐1】In a digital age, we almost never write things by hand. However, multiple studies have shown that this act has many benefits.
New brain research, led by researchers at the Norwegian University of Science and Technology, confirms the same: choosing handwriting over using a keyboard results in better learning and memory.
The study was conducted using equipment to track and record brain wave activity. The participants included 12 young adults and 12 children. This is the first time that children have participated in such a study. Each subject was asked to write by hand and type on a keyboard while wearing a hood with over 250 electrodes. The sensors in the electrodes are very sensitive and pick up the electrical activity that takes place in the brain. Each examination took 45 minutes per person.
The results showed that the brain in both young adults and children is much more active when writing by hand than when typing on a keyboard. According to Van der Meer, plenty of senses are activated by pressing a pen on paper, seeing the letters written and hearing the sound made while writing. These sense experiences build contact between different parts of the brain, opening the brain up for learning.
Van der Meer believes that the results stress the importance of children being challenged to draw and write at an early age, especially at school. ''Learning to write by hand is a bit slower process, but it's important for children to go through the tiring phase of learning to write by hand," she said.
The hand movements used to form the shapes of letters are beneficial in several ways. "If you use a keyboard, you use the same movement for each letter. Writing by hand requires control of your fine motor skills and senses. It's important to put the brain in a learning state as often as possible," Van der Meer added.
1. How was the study carried out?| A．The test lasted 45 minutes in total. |
| B．There were 24 adults participating in the research. |
| C．Equipment was used to collect data during the research. |
| D．Each participant was asked to wear a hood with 250 electrodes. |
| A．using a keyboard. | B．seeing the letters written. |
| C．copying the sound. | D．opening the brain up for learning. |
| A．Recording ideas on the tape. | B．Typing articles into the computer. |
| C．Writing shopping lists on the phone. | D．Taking notes by hand during the lecture. |
| A．It's a slow process to learn to write. | B．It's a tiring process to write by hand. |
| C．It's vital to get children to draw and write. | D．It's beneficial to get kids to type on a keyboard. |
【推荐2】Cold weather during winter months may keep many people from leaving home and running in the open air. However, a new study shows that the drop in temperature is a good reason to run. In fact, researchers say, running in cold weather helps improve one’s performance.
Many people say running in the winter can be difficult. Two reasons are the low temperatures and bitter winds. Yet many runners might find it easier than running in hot weather.
That could be because lower temperatures reduce stress on the body. When you run in cold weather, your heart rate and the body’s dehydration (脱水) levels are lower than those in warmer conditions. The body needs less water on a cold day than in warm weather.
This information comes from sports scientists at St Mary’s University in London. John Brewer is a professor of Sport, Health and Applied Science at St Mary’s.
For this study, he and other researchers put a group of people into a room they called an “environmental chamber”. The researchers then recreated summer and winter weather conditions in the room. The test subjects were asked to run 10km under both conditions. Brewer says he and his team recorded biological measurements of the runners. “We’ve got a group of subjects into the environmental chamber, we’ve changed the conditions to replicate the summer or winter and we’ve got them to run 10km under both of those conditions and taken various measurements on each runner while they’ve completed their 10km.”
Brewer says every movement runners make produces heat. He explains that one way in which we lose heat is by sweating. The body loses heat through droplets of sweat. He says the body also loses heat by transporting the blood to the surface of the skin.
1. What can we know about running in winter?| A．It improves the function of body. | B．It increases pressure of the body. |
| C．It makes your heart rate higher. | D．It needs more water than in summer. |
| A．Researchers interviewed the subjects. |
| B．Subjects were asked to run in winter and summer. |
| C．Subjects built the “environmental chamber”. |
| D．Biological measurements of the runners were recorded. |
| A．Combine. | B．Copy. | C．Recognize. | D．Decorate. |
【推荐3】Velcro® is a hook-and-loop(钩和环, 粘扣的) device that is commonly found on a wide range of products, such as shoes, jackets, and a lot of other equipment in offices, kitchens, and garages. It’s also the name of the company that originally created the “thing” generally known as Velcro®.
George de Mestral, a Swiss electrical engineer, is the inventor of Velcro®. How he came to the idea of actually making this thing that we call Velcro is a truly incredible story.
One fine morning in 1948, Mestral went for a walk with his dog. After returning from the walk, he found that some seeds get stuck to the dog’s fur. However, the man’s attention was turned to his own trousers, where many similar seeds also attached.
Upon closer examination, he observed that there were many small hooks in the seeds that stuck firmly to the loops in the fabric of his trousers. The first idea for what would eventually become Velcro struck him like a lightning. If he could artificially recreate the same thing, by making pairs of hooks-and-loops that stick to each other firmly, then there would be almost no need to tie things up all the time to secure them, nor would zippers(拉链), which were quite popular in those days, be necessary any longer. He decided to call the product he formed Velcro®.
Like many inventions, Velcro® also faced a great deal of criticism, but Mestral stood by his design and continued to make structural changes to enhance its bonding strength. He worked with a Frenchman to come up with a perfect hook -and-loop device. Mestral patented Velcro® in 1955.
Velcro didn’t do too well initially; much of that was due to its lack of aesthetic(美学的) appeal. It came in dull colors and often looked quite “unattractive”. But soon, even NASA helped to boost Velcro®’s image by using it in a lot of equipment that went into space along with astronauts.
1. What can we know about Velcro®?| A．It’s been edged out by zippers. | B．It’s an established shoe brand. |
| C．It’s a nature inspired invention. | D．It’s a hook commonly used in offices. |
| A．Observant. | B．Demanding. |
| C．Overconfident. | D．Weather-beaten. |
| A．Uncaring. | B．Highly critical. |
| C．Positive. | D．Fiercely divided. |
| A．A famous inventor. | B．A remarkable creation. |
| C．An unexpected discovery. | D．An unforgettable experience. |
【推荐1】Most French people eat dinner at 8 pm or later. Some French families, especially if they do not have young children, may start dinner as late as 9 pm or 9:30 pm. The first time I went to France, I was confused that my host family hadn’t had dinner by 7 pm yet. “Are they going to skip dinner?” I wondered.
It’s not clear to me why French people eat so late. Alysa Salzberg, a French writer, guesses that the later meal time develops from typical French working hours. “French people eat late because most standard job hours are 9 or 10 to 6 instead of 9 to 5,” Alysa explains. “So, by the time everyone gets home and a meal is prepared, it’s about 8 pm.”
French people usually eat a smaller dinner, such as soup or salad with bread and dessert. Considering French people famously don’t snack, they must survive a long break between lunch and dinner. The solution is that lunch is the biggest meal of the day. Americans and people from other countries may have a simple sandwich for lunch, but French lunches are typically more considerable. I remember having a huge lunch at the host school with other French students last month. The lunch came with salad, bread, a main dish, cheese and a yogurt. It seemed like too much food the first time I saw it.
In addition, French people never eat on the way. It’s unusual to see French people eating a cheeseburger from a McDonald’s while sitting in their cars. I don’t remember seeing French people eating while walking in the street or on the subway in Paris either. French people consider it important to sit down at a table to eat and even eat a hamburger with a knife and fork.
1. Why do the French eat dinner late in Alysa Salzberg’s opinion?| A．They have a big lunch. |
| B．Dinner is less important to them. |
| C．Dinner dishes take a long time to cook. |
| D．They get off work late. |
| A．simple | B．plentiful | C．expensive | D．delicious |
| A．Cars play an important role in French life. |
| B．Fast food is not popular in France. |
| C．The French pay great attention to eating manners. |
| D．Eating in public places is not allowed in France. |
| A．He is an overseas student in France. |
| B．He enjoys French food very much. |
| C．He works as a magazine writer. |
| D．He agrees with the French way of life. |
【推荐2】There are usually few things people want to do less than housework. But while washing the dishes and dusting the shelves seem like trouble some things. A new study has found just how important they are to our general health and happiness.
In fact, scientists now believe cleaning the house is more important to mental and physical health than other factors, such as the area you live in or how much you earn. Researchers at Case Western Reserve University say doing housework is helpful because of the exercise it takes to get the daily job done, which in turn affects mental health.
Dr. Kathy Wright and a research team at the university’s Frances Payne Bolton School of Nursing wanted to find out how property (财产), education, environment and health behaviors, like smoking, affect an older person’s health. The study’s 337 participants, from 65 to 94 years old, had to have at least one chronic (慢性的) illness which prevented them from doing at least one basic daily task, such as bathing and dressing.
Dr. Wright said she was surprised to learn that doing housework and keeping their property affected the participants’ mental and physical health more than other factors. “House cleaning kept them up and moving, ” said Dr. Wright. “A clean environment is helpful in treating some illnesses. And poverty (贫穷) did not directly affect mental or physical health. ”
The study proved what Dr. Wright had observed in her visits: people living in a dirty environment seemed less satisfied than those in a place that was neat and tidy. Dr. Wright hopes the study shows how important it is for older people with chronic illnesses to continue physical activities, such as doing reaching exercise while sitting, standing up and sitting down in a chair.
1. What can we infer from the first paragraph?| A．Most people don’t like doing housework. |
| B．Most people are too busy to do housework. |
| C．Most people do less housework than before. |
| D．Most people don’t know how to keep healthy and happy. |
| A．limited the participants’ moving areas to certain places |
| B．tried different treatments for the participants’ illnesses |
| C．observed the changes of the participants’ behaviors |
| D．chose those who were weak as their participants |
a. learn to share
b. do some exercise
c. learn to be responsible
d. keep the house clean and tidy
e. enjoy staying with family members
f. improve our mental and physical health
| A．a, c, e | B．b, d, f |
| C．c, d, f | D．d, e, f |
| A．people’s different attitudes towards housework |
| B．how to improve mental and physical health |
| C．the advantages of doing housework |
| D．the best ways to do housework |
【推荐3】The world’s elderly population is increasing. The number of older people ---those age 60 years or older ---is expected to double by 2050 and is growing faster than all younger age groups across the globe. That comes with an increasing need for caregivers which can provide 24-hour care, not only at hospitals or nursing homes, but also at private homes.
Already, caregiving robots are programmed to ask questions a nurse would ask and can keep an eye on patients for falls. These robotic assistants are expected to become increasingly marketable and reach 450,000 by 2045 because of the expected caregiver shortage in the USA.
“Unluckily, the hard structure of present caregiving robots prevents them from a safe human-robot interaction(互动), limiting their assistance to only social interaction and not physical interaction,” said Ramses Martinez, an assistant professor in Purdue’s College of Engineering . “After all, would you leave babies or old people in the hands of a robot?”
Recent advances in material science have enabled the production of soft robots with deformable (可变形的) bodies or the ability to reshape when touched , but today the complex design prevents the use of this technology at home .
However, Martinez and other researchers have developed a new design method which shows promise in enabling the production of soft robots using a 3D printer.
“The soft machines move like humans. Their ability to change their body structure and movement to adapt ( 适应 ) to a wide variety of environments will improve caregiving greatly,” says Martinez .
The researchers are looking for partners to test and bring their technology to market.
1. What does the underlined word “That” in Paragraph 1 refer to?| A．The younger age group |
| B．The group of older people |
| C．The population across the globe |
| D．The growth of the elderly population |
| A．They can’t provide safe physical interaction |
| B．They can’t communicate with patients |
| C．They can’t watch patients for falls |
| D．They can’t provide 24-hour care. |
| A．It requires a special kind of 3D printer. |
| B．It makes the production of soft robots simpler. |
| C．It has been put onto the market. |
| D．It is hard for users to master. |
| A．The robot industry in the future |
| B．Effects of population ageing |
| C．Robots for the elderly created with 3D printers |
| D．The development of caregiving robots |
