People in the western state of California who are in the United States illegally can now request a driver's license. The law went into effect on January l. California is not the first American state with such a law, but it has the largest number of illegal immigrants. More than a million people began to request licenses shortly after the new state law went into effect. Among them was Christian Alvarado. Mr. Alvarado entered the United States from El Salvador eight years ago without permission from the U.S. government. Some call such people "illegal immigrants." Others call them "undocumented immigrants".

    Mr. Alvarado thinks it so exciting, for he has been waiting for the license for a long time. But some are worried that their personal information will be used to find them and deport them. Armando Botello is a spokesman for the California Department of Motor Vehicles, or DMV. He says people should not be afraid, for such information will not be shared.

    The new licenses are the same as licenses given to citizens except that they have the words "Federal Limits Apply". That means the license cannot be used to travel on an airplane or enter a federal building. Ana Garcia, working at the Central American Resource Center, says some illegal immigrants fear those words will be used to abuse them. Civil rights groups say the police and others will not.

    Dan Schnur, a political scientist at the University of Southern California, said that the main argument against the new law is that it rewards illegal behavior. But Professor Schnur argued that young, white Americans generally support immigration reform, including giving driver's licenses to illegal immigrants

    "It's simply because they grew up in a much more multicultural society than their parents or their grandparents did." Professor Schnur says he believes the changes in beliefs about illegal immigrants that have taken place in California will spread throughout the United States.

    Darek Fidyka, a 38-year-old Bulgarian, had been paralyzed (瘫痪的) from the chest down for four years after a knife attack. Scientists from Britain and Poland took cells from his nose, transplanted (移植) them into his back and re-grew his spinal cord (脊髓). Now he can walk and even drive a car. The doctors were delighted but said it was the first step in a long journey.

    The breakthrough came after 40 years of research by Professor Geoff Raisman, who found that cells had the possibility to repair damage to nasal (鼻腔的) nerves, the only part of the nervous system that constantly re-grows. “The idea was to take something from an area where the nervous system can repair itself and put it into an area that doesn't repair itself,” Professor Raisman said.

    Polish doctors injected (注射) the nasal cells into Mr Fidyka's spinal cord above the injury and used some nerves from his ankle to form a bridge across the damaged tissue. The nasal cells appear to have caused the spinal nerves to repair themselves.

    Professor Raisman achieved this with rats in the late 1990's, but this is his greatest success. “I think the moment of discovery for me was Christmas in 1997 when I first saw a rat, which couldn't control its hand, put its hand out to me. That was an exciting moment, because I realized then that my belief that the nervous system could be repaired was true.”

    Doctors chose the easiest case for their first attempt—it might not work for others. But there is a real sense of hope that an idea once thought impossible has been realized.

    David Nicholls, who helped provide money for the breakthrough, said information about the breakthrough would be made available to researchers across the globe.

    “What you've got to understand is that for three million paralyzed people in the world today, the world looks a totally brighter place than it did yesterday,” he said.

    Singapore is building an airport where indoor trees, waterfalls and a 'rain vortex' sit alongside check-in queues, waiting rooms and baggage carousels(传送带).

    Where once sat a car park, there will soon be thousands of trees and plants across 22,000 square metres of landscaped indoor parklands. This will be joined by a 40m-high indoor waterfall, expected to be the world's tallest. These are the plans for the new 3.5 hectare 'Jewel' development at Singapore's Changi Airport, scheduled to open in 2018; a five-story, 134,000 square metre complex, mixing natural outdoor plants with modern airport facilities.

    “The aim behind the introduction of such lush(茂盛的) landscaping is purely to provide all visitors with a memorable experience, one where they are surrounded by nature and greenery,”says Philip Yim, Chief Executive Officer of Jewel Changi Airport Development.

    Promised sustainability（持续性） measures include “extensive usage of photovoltaic panels（光电板）”to produce renewable energy, as well as encouraging the use of natural lighting and a “high efficiency” air-conditioning system.

    The indoor waterfall, named the “Rain Vortex”, will make use of special lighting effects to change at night into what is promised to be a dramatic light and sound show. “The Rain Vortex is one example of how sustainable design plays an important role in the planning of the attraction,” says Yim. 'In the event of a rain storm, the power of the rain water will flow naturally through the oculus. The excess rain water collected will be used for irrigation of the landscaping at Jewel.'

    Yim quotes the popular reputation Singapore enjoys as “the garden city”, where greenery is recognised as an essential part of the urban landscape, an attractive image which clearly inspires Jewel's design.

    However, it remains to be seen whether, beyond the aesthetic (审美的) appeal, Jewel can add genuine environmental things to something as un-environmental as an international airport.

    It was one of those days when there was way too much to do. I had fallen behind in most of my household chores.

    After breakfast, I sat down at the computer to write an article. My youngest daughter, Julia, walked toward me. "But, Mommy, I thought we were going to do something fun today," she said. "Since it's our day off from school." "I know it's your day off, but it's not Mommy's day off," I explained.

    "Can you play a game with me?" she begged. "Like Candy Land? Or beauty shop?" I sighed. I really didn't have time to play. I desperately needed to get some work done. But then I had an idea. "Can we play beauty shop while I work?" So I got my article done, and my toenails(脚趾甲) painted at the same time. My oldest, Austin, volunteered to fix lunch so I could keep working. Shortly after lunch, we went to the grocery store and I got what I needed. Back at home, the kids decided to play "grocery store". For the remainder of the afternoon, I cleaned house, folded laundry, and started dinner. The kids continued with their game until my husband, Eric, walked through the door.

    He saw me and smiled. "So how was the kids' big day off today?" I began to explain that we hadn't done anything special. But my two middle kids, Jordan and Lea interrupted me. They told their dad, "We had such a special day today, Dad! It was a blast!" I looked at my children's faces. They were lit up with excitement.

    I nodded, realizing how right he was. Happiness is far more about our attitude than our circumstances. I hugged my kids and thanked them for reminding me to look for happiness in the little things. Julia smiled and said, "And the little things that make you the happiest are us, right, Mommy?" Wow, my kids sure are smart.

    Global warming is the process of earth's atmosphere heating up. Over the last 100 years, the average temperature of earth's atmosphere has gone up 1 Fahrenheit. The weather has not changed exactly the same way in every area of the planet. But scientists think that the rise in average temperature is already affecting the earth, s climate.

    Many scientists now believe that global warming is caused by cutting down trees, producing more trash, and polluting the environment are some of the reasons that the temperature has gone up. Many scientists believe that the biggest causes of global warming are new human technologies that release greenhouse gases into the atmosphere.

    The greenhouse effect is not new. Certain gases in the atmosphere, like carbon dioxide, nitrous oxide and methane, prevent heat energy from escaping back into space. In the past, the climate didn't change much because nature produced just the right amount of greenhouse gases to deal with it.

    Today, most scientists are pretty sure that the rising temperature can't be blamed on nature. Ever since the industrial revolution in the 1700s, humans have relied on machines for daily life. And many of those machines give off a lot of greenhouse gases. An increase in the release of greenhouse gases from human activities is throwing nature off balance.

    The climate is a very complicated thing, but many scientists agree that the rising atmospheric temperature has already damaged the environment. Sheets of ice, called glaciers, are melting in Antarctica and other parts of the globe. As glaciers break off and melt into the oceans, they are adding warm water to the oceans and causing the sea level to rise.

    Over the past last 100 years, the sea level has risen 6-8 inches around the world. That means land along the coasts is beginning to disappear under water. Bigger and warmer oceans are also adding to other weather problems caused by pollution in the atmosphere. Some places have received more rain, others have had bigger storms and a few areas in the world have experienced unusual droughts.

Much of Earth is unexplored. An ocean census (普查) hopes to change that.

"Earth" has always been an odd choice of name for the third planet from the Sun. After all, two-thirds of its surface is covered not by earth at all, but by oceans of water.

Because humans are land animals, most of the Earth remains under-explored. Marine (海洋的) biologists think the oceans might host more than 2 million species of marine animals, of which they have so far identified perhaps a tenth.

A new initiative hopes to change this. Launched in London on April 27th, Ocean Census aims to discover 100, 000 new species of marine animal over the coming decade. It is backed by Nekton, a British marine-research institute, and the Nippon foundation, Japan's biggest charitable foundation. Its first ship, the Norwegian icebreaker Kronprins Haakon, set sail on April 29th, bound for the Barents Sea.

The initiative is happening for two reasons. One is that the longer scientists wait, the less there will be to identify. Climate change is heating the oceans, as well as making them more acidic (酸的) as carbon dioxide dissolves goes into the water. Already around half the world's coral reefs (珊瑚)—thought to be home to around 25% of all ocean species—have been lost. Oliver Steeds, Nekton's founder, says that one of Ocean Census's priorities will be identifying species thought to be in the greatest danger from climate change. The second reason is technological. Marine biologist s find about 2, 000 new species a year, a rate hardly changed since Darwin's day. Ocean Census is betting it can go faster.

Exactly what the new effort might turn up is impossible to predict. But history suggests it will be fruitful. Half a century ago scientists discovered hot vents (喷口) on the sea bed. These days, such vents are one possible candidate for the origin of all life on Earth. There are more practical benefits, too. Many drugs, for example, come originally from biological substance. An ocean full of unidentified life will almost certainly prove a rich mine from which to mine more.