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Two major practical difficulties stand in the way. First, EVs currently suffer from limited battery ranges compared to conventional vehicles, which can travel longer distances on a full tank of fuel. Second, charging infrastructure (基础设施) remains underdeveloped, with charging points still insufficient in most regions. These factors contribute to "range anxiety" among potential buyers, slowing the shift to electric transport.

On the technological front, solid-state batteries are viewed as a promising breakthrough. Though currently used mainly in consumer electronics like smartphones, they are expected to enter the car market in the coming years, offering quicker charging times and an extended driving range. This could significantly enhance the appeal of EVs to the general public.

Economically, high initial costs continue to be a barrier. However, some countries have introduced policy supports, such as tax reductions, purchase subsidies (补贴), and dedicated traffic lanes for EVs, helping to boost adoption rates. Norway serves as a leading example, with the highest number of electric cars per person globally.

Nevertheless, experts like Colin Herron caution that EVs alone do not equal a zero-carbon future. Their environmental impact depends heavily on how the electricity used to charge them is generated. If the power comes mainly from fossil fuels, the overall emission reduction is limited. In addition, manufacturing EVs — especially their batteries — carries a substantial carbon footprint. Therefore, a truly sustainable transport system may require not only cleaner cars, but also greater use of public transport and a societal move toward fewer and shorter private vehicle trips.

Previous studies identified that naturally occurring opioids (阿片类物质) in the brain play a crucial role in sugar desire. The main producers of these opioids are nerve cells located in a brain region that adjusts appetite, metabolism and hormones. Known as pro-opiomelanocortin (POMC，前阿片黑素细胞皮质激素) nerve cells, they also control feelings of satiety after eating.

To explore whether the cells also drive thirst for sugar, Henning Fenselau at the Max Planck Institute for Metabolism Research in Germany and his colleagues tracked the opioid signals the POMC cells send in the brain. The researchers monitored the activity of nerve cells in these regions as mice ate their usual food. When the animals seemed to be full, the team gave them a dessert of sugary chow. The results showed that, on average, the activity between the POMC nerve cells and the PVT (丘脑室旁核) roughly multiplied during dessert consumption, and even rose sharply before the mice started eating the sweets, proving this nerve pathway directly fuels sugar desire. When the team blocked signals from POMC nerve cells to the PVT, the mice consumed 40 per cent less dessert.

"The cell types, which are extremely well known for making people feel full, also release signals that cause the appetite for sugar, and they do so particularly in the state of being full," says Fenselau. "This would explain why animals — humans — over-consume sugar when they're actually full."

Chen calls herself "an artist made of paper", believing paper shapes both her creations and her thinking. Traditionally, the cut-out parts are abandoned and the intact (完好的) pattern is what people keep. Chen challenges this logic. "Can the hollow (镂空) itself become the main subject?" she asked. This reflection shaped her exhibition displayed on Paris's Champs-Elysees during the 2024 Summer Olympics. Chen imagines a world where paper is not just a craft material but the foundation of an entire civilization, presenting everything in symmetrical (对称的) paper-cut forms to convey a society built on control and balance.

"What matters to me is the logic of subtraction (减法)," she explained. "The interaction of solid and void (实与虚) in paper-cutting represents Eastern philosophies of coexistence." Surprisingly, when she introduced her work to Thomas Bach, president of the International Olympic Committee, he immediately brought up "yin and yang", making her realize it is a universal language of balance.

Another signature of Chen's work is her brave use of pink. Pink once was off-limits to her, for it symbolized the "good girl" image. It was not until 2016 that she reinterpreted pink as the natural color of Asian skin, a color of life itself and began to embrace it. Her pinks changed from soft to bright and striking. The shifting shades of pink mirror her growing courage to break free from old ideas.

In her view, the modern vitality of paper-cutting does not lie in color, form, or technique, but in the contemporary spirit and ideas it carries. "I want my works to draw attention, but more importantly, to make people think about the stories and realities they reflect."

Travelex Insurance Services provides three different kinds of trip protection. The Essential, Advanced and Ultimate plans are the company's single-trip travel insurance choices. Travelex's multiple optional upgrades include cancel for any reason coverage, rental car protection, adventure sports coverage, pet care benefits and more. The highest-tier (级) Ultimate plan can also include preexisting conditions (既往症状) coverage if you buy the policy within 21 days of the first fee you pay on the trip.

World Nomads is known for inclusive coverage across its plans for more than 250 adventure and sports activities, which many other providers only cover if you purchase an add-on. The company has three single-trip plans (Standard, Explorer and Epic). The single-trip policies cover trip cancellation and interruption, trip delays, delayed or damaged luggage, emergency medical issues. The optional cancel for any reason upgrade is available with the Explorer and Epic plans; preexisting conditions are also covered with those two plans.

Allianz has been a reputable name in the insurance business since it was established in 1890. The company offers 10 travel insurance plans, including single-trip options, annual plans, and specialized car rental and emergency medical plans. The key plans for an individual vacation are OneTrip Basic, OneTrip Prime and OneTrip Premier. Basic is the most affordable. Prime is considered as the company's "most popular", and Premier is the option with the most comprehensive coverage.

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In the morning，I write this to-do list：

⒈Go to the bank.

⒉Get a nice haircut.

⒊Pick up my academic statement from college.

⒋Submit my poems.

I think， "That's enough for one day."

Up until a few years ago，I didn't aim to be anywhere.And in order to be nowhere，one does not need a to-do list as a guide.Focusing only on the most pressing matter in front of me was enough.Let the next urgent moment think for me.

My mother had tried to teach me about planning my day ever since I was 10.But I never practiced it until I was 25 and done with college.That's when I awoke to the fact that I didn't want to waste any more time.I live in Nigeria，where life and success can be difficult.There seem to be many roads to failure here.

I grew up seeing my mother firmly in charge of her day.She knew—and still knows—where she needed to be at every moment，in every detail.She may not be good at singing，acting，or sports.But she is excellent at planning.Every day she writes a list.I never understood why she had to write down a list that consists of items you can easily hold in your mind."Your to-do list is like your second mind，"she told my younger self."If you ever feel lost or overwhelmed，you consult your second mind."

I didn't understand what she meant by"a second mind"until I seemed to lose my first mind in my everyday life.Sometimes，it seems as though it's the rainy season in my mind，flooded with confused and distracting thoughts that lead nowhere.I need a second mind—now!

As I sit in the barbershop awaiting my nice haircut，a friend asks me， "What's next？"

"Pick up my academic statement from college，"I say."Then submit my poems."

"You've got it figured out like a granny，"he jokes.

"No，"I say， "like my mother."

Science serves as a powerful tool for unlocking the mysteries of the universe，but understanding its limitations is essential for its effective application.There are occasions where I have used the handle of a knife as a hammer（锤子），but the result would have been better if I' d had a more suitable tool at hand.As far as science goes，it is really good at testing things that are testable，but not so for those that are not.

We can do，and have done，an impressive amount with our brains.But there are limits.Sometimes these limits go away if we keep at it for long enough—we just need better facilities and experiments to get the answer.Breaking new ground in modern science this way can be costly.Next-generation supercomputers or incredibly large telescopes are expensive，yet these may be required to find answers to some of the unsolved mysteries of the universe.

Sometimes the limits we encounter in trying to unlock the nature of the universe are cognitive（认知的）.Think about this：human DNA is only about 1.2 percent different from that of chimps（黑猩猩）.Chimps are smart，no question.But could you teach them advanced mathematics？What if our DNA were another 1.2 percent further evolved than it is？What might our brains be capable of then？The level of abstract thinking might be un-imaginable.

Sometimes the limits we hit are fundamental.There are laws of nature we may never be able to understand，however advanced our brains might be-come.There are experiments we might never be able to perform.We may never be able to test what caused the universe to be created，and what caused the cause of the universe being created.This is where science may never break through.

For something to be considered scientific，it must，by definition，be testable.There is a problem here：it may not need to be testable right now，but it must be testable at some point in the future by experiment.If an idea is untestable，that doesn't mean it is wrong.It means it is untestable for now.These untestable ideas also happen to be some of the most interesting ones，probably because they' ve puzzled humanity for centuries.

All animals take in oxygen from the air they breathe in，and release CO2 from their blood when breathing out.Most mammals（哺乳动物） can't directly detect oxygen levels in the blood supplied to their tissues.Instead，they rely on the rising level of CO2 in their blood to signal that they might need to take a breath.But a recent study published in Science suggests seals（海豹） can sense the amount of oxygen in the blood，and change their diving behavior in response.

To find out if oxygen levels affected seal behavior，Professor McKnight at the University of St.Andrews and his colleagues created a special section in a pool where young seals were held.In one corner，there was a breathing chamber（呼吸室），where they were sheltered from the rain and the wind.

The breathing chamber was surrounded by panels that prevented surface swimming，yet swimming below the surface for about 200 feet would give the seals access to a feeder where they could eat as much fish as they liked.Once the seals got familiar with the setup，the researchers started to gradually change the composition of the air in the breathing chamber，in-creasing or reducing the levels of oxygen and CO2 to see an effect on their behavior.Sure enough：the higher the level of oxygen，the longer the seals stayed at the feeder.

The finding suggests that seals don't just physically respond to oxygen levels by changing their heart rate or breathing，but that they are sufficiently aware of them to change their behavior.This ability would put seals in a class beyond any land mammals that have been tested.Since oxygen levels on land remain stable，humans don't seem to have evolved（演化） to notice low blood oxygen levels，sometimes not even when they're about to pass out in free-diving.

Therefore，in free-diving without oxygen tanks，accidents are quite common.Our reliance on sensing CO2 levels in our blood instead of oxygen may be to blame.Actually，this is a perfectly reasonable strategy on land，where growing CO2 tends to signal breathing issues.But when holding our breath during diving，relying on CO2 levels is risky，especially on repeated dives.Because every time we surface and breathe in，our sensitivity to CO2 is decreased，even if its levels are already high，and this increases the chance that a person will，without awareness，pass out before they get to the surface.

My great grandmother received the dollhouse（玩具小屋） from a family friend back in the late 1800s.It was then passed down from generation to generation.I was seven when I discovered it under-neath the tree on Christmas morning.

In our house，Mom set up a sewing area.I sat at her sewing machine，my feet barely reaching the presser foot.Mom bent over me，her hands on mine，gently guiding small bits of cloth under the needle to create dollhouse bedding.She also taught me to make mini-blankets.With a little paint and glue，Mom demonstrated that anything could be turned into dollhouse furniture.I learnt to view the world as a place of possibility.I spent hours of my girlhood sitting before my dollhouse，telling made-up stories，and creating miniatures（缩微模型）.But eventually school activities took over，and the dollhouse was moved to the attic（阁楼）.

Over the next 40 years，the storytelling skills I'd practiced with the dollhouse grew into novel writing skills，and I developed a career as an author.One day，after hours of working on my fourth book，I took a break by surfing the Internet and happened to notice the beautiful dollhouses people posted on social media.They reminded me of mine.I went to the attic，brought it back to my room and started updating it.

During the mindless hours of sewing and furnishing（布置家具），I listened to audiobooks about the history of dollhouses，learning that they were not invented for play.There's a long，rich history of people in hardship turning to dollhouses to find comfort.They weren't produced as toys until mass production became standard after 1945.This inspired me to create a novel where art saves the day.

The truth was I myself needed art to save the day.Mom was then slip-passing away from me owing to progressive memory loss.The only topic we could discuss with any genuine joy was the update of the dollhouse.She loved retelling its history—those old memories.Mom didn't find it strange at all that her 50-year-old daughter was updating the dollhouse.She just thought it fun and beautiful.And it was.It was a world where Mom and I were at our best together.

Welcome to our university's Botanic Garden—plan your visit，and find out about what we do!

You can either pay at the Ticket Office on arrival，or book your tickets online.Please note：Tickets cannot be used on any date other than the one they were booked for and are non-refundable（不可退款的）.

Guidelines for Visitors

The Garden is an active research facility and a living museum with a collection of over 8，000 plants.

Please bear in mind some simple rules for your visit：

•Only trained working dogs are permitted to enter the Garden.

•Children must stay with a grown-up at all times.

•Stick strictly to the paths and lawns（草坪）.

•Do not climb the trees.

•Please do not pick any part of a growing plant.

•Cycling and ball games are not permitted in the Garden.

Guided Tours in the Garden

With over 8，000 plant species and a wonderful range of gardens and plantings to enjoy，there is something for everyone at the Garden，and many different aspects to appeal to a wide variety of interest groups.

Free Drop-in Weekend Tours

Enjoy a free-of-charge Garden tour with one of our expert guides，taking in the seasonal highlights of the Garden.

Our weekend tours are available every Sunday at 11：30 a.m.and 2 p.m.throughout the year.During the months of January and February these tours focus on the Winter Garden，Snowdrops and general winter interest.

The free tours last one hour and start from the Fountain，near the MainLawn.

Group Tours

Our experienced volunteer guides will help you enjoy the highlights and provide some of the background history and development of this amazing garden.

These 90-minute，pre-bookable tours are ideal for adult groups wishing to make the most of their visit to our 40-acre site.Please visit the Group Guided Tours page for more details.

Life is a road full of minor inconveniences and major setbacks，which everyone faces，

1 wealth or social rank. That is why optimism，the ability to see the 2 side of every negative situation，is key to success.

What made optimism so meaningful to me was when I 3 the A team of the basketball club for the upcoming season. I had always been the starting point guard，and my4 on the A team was something I took for granted. However，I only made the B team，5 I worked my hardest. I didn't understand why until I saw the new A team，crowded with players that all6 me. 

I had to give the B team a chance. But to my7 ，the play level was much lower than what I was used to. I lost the drive I'd had before and gradually became8 . 

One day I came across a social media post of another basketball team，whose point guard was much more9 than her teammates. When her team-mates made multiple mistakes10 ，which cost them several points，I expected her to be upset，but11 ，she patted her teammates on the back and comforted them. As I watched her more，I noticed that she led her team，always 12 and uplifting her teammates. 

The realization hit me like lightning. What I thought was a13 turned out to be a valuable opportunity，presenting a rare chance to develop14 . So，I started using my15 to be a leader for my team. When our coach needed a（n）16 ，I was the first to raise my hand. When my teammates needed help with a skill，I 17 taught them over and over again. My effort paid off as I18 remarkably not just as a player，but as a person—some-thing I could have never achieved on the A team. 

When facing challenges in life，some people19 them with optimism，while others tend to complain. Optimism is a palette（调色板），with which you can paint your own light in the darkness，shelter in a storm，and most importantly，a better20 of yourself!

—Congratulations!____.