Coral reefs are,in fact,a necessary part of our ecosystem and provide opportunities for human beings to gain a better understanding of the ocean.Unfortunately,they're also disappearing faster than ever.

    According to a warning by the US National Oceanic and Atmospheric Administration(NOAA) on Oct.8,the world is in its third recorded global coral bleaching（白化）since 1998 and 2010.This means no place with coral has been spared,as coral reefs are coming into contact with increasingly warm seas,which is leading to them dying off in large numbers.

    Coral bleaching is like human cancer.It happens when corals are under stress from changes in light,nutrients,or temperature.This causes the coral to drive away the symbiotic algae（共生藻类）,living within their tissues（组织）, which play an important role in providing food for coral while making it colorful.Without the algae,coral reefs become pale and weak.In some cases they are not able to recover and eventually die off.

    The current coral bleaching event started back in late 2014 and continued into this year with no signs of stopping.The BBC reports that 35% of coral reefs in the world will likely be affected,and an estimated 4,633 square miles (about 120,000 square kilometers) of coral reefs could die.

    The loss of coral reefs is no small matter.Although they only take up 0.1% of the ocean floor,coral is home to about 25% of marine life.This isn't just a problem for divers and fish,as Eakin pointed out.Coral reefs are important globally,he added,as they protect shorelines,produce money in tourism,and help provide food for 500 million people worldwide.So people cannot overlook the environmental,economic and social effects of the loss.

    The NOAA warning about coral bleaching came just about two months before a global climate summit（峰会）in Paris,where hundreds of world leaders will attempt to work out a plan to fight climate change.

    Oceans will be a key subject during the summit,and Eakin says there's an "absolutely urgent need" for action.

    Antarctica(南极洲)'s melting ice, which has caused global sea levels to rise by at least 13.8 millimeters over the past 40 years, was thought to primarily come from the unstable West Antarctic Ice Sheet(WAIS). Now, scientists have found that the East Antarctic Ice Sheet (EAIS)—considered largely unaffected by climate change—may also be melting at an unexpectedly rapid speed.

    The WAIS, whose base is below sea level, has long been considered the most likely to break down. Besides gravity, a deep current of warm water slips beneath the sheet, melting it from below until it becomes a floating shelf at risk of breaking away. In contrast, extreme cold and a base mostly above sea level are thought to keep the EAIS relatively safe from warm waters.

    But as greenhouse gases warm much of the planet, driving stronger polar winds, some scientists think warm water carried by a circular current will start to invade East Antarctica's once unassailable ice. A cooperation of more than 60 scientists last year, published in Nature, estimated that the EAIS actually added about 5 billion tons of ice each year from 1992 to 2017.

    Eric Rignot of the University of California, Irvine, and colleagues combined 40 years of satellite imagery and climate modeling and found that overall Antarctica now sends six times more ice into the sea each year than it did in 1979, with the majority coming from West Antarctica. But East Antarctica was responsible for more than 30% of Antarctica's contribution to the 13.8-millimeter sea level rise over the past 40 years. “The more we look at this system the more we realize this is fragile,” Rignot says. “Once these glaciers become unstable there is no red button to press to stop it.”

    Rignot hopes the study brings greater attention to a part of Antarctica that has traditionally been understudied. Helen Fricker, a glaciologist (冰川学家) in California, agrees. “We need to monitor the entire Antarctica and we just can't do that without international cooperation.”

    Like all big cities, Paris has a traffic problem: lots of cars, lots of traffic jams (阻塞) and lots of pollution from exhaust fumes (废气). So the city began a scheme (计划) to improve the situation.

    Under the Velib scheme ('Velib' comes from vélo liberté, or 'bicycle freedom') people can take a bicycle, use it for as long as they want, and then leave it at the same or another bicycle station. The first half-hour on the bike is free, but if you don't return it after 30 minutes, you have to pay. But it's only €1 a day or €29 a year! The bicycles are heavy (25 kg), and they are all grey and have baskets. There are about 20,000 of them in the city, and around 1,450 bicycle stations. So there are a lot more Velib stations than the 298 subway stations!

    Paris is not the first city to have a scheme like this. But not everybody thinks it's a great idea. One Parisian said, 'These bicycles are only for short journeys. If people want to travel across the city, they won't use a bicycle—they'll still use their cars.'

    A city spokesman said, "The bicycle scheme won't solve all our traffic problems, of course. But it might help reduce air pollution. Traffic, together with factory fumes, is a big problem. There aren't any simple answers to traffic problems and pollution in cities. But unless we do something now, there will be more traffic jams and temperatures will continue to rise, so the problems in our environment will get worse. The bikes might help people to lead a healthier life, too."

    It is common to see many different kinds of insects while spending time outside in the summer. Some of them do not trouble people and can even add beauty to the natural environment. Other insects can harm the environment or humans. The population of these insects seems to stay large and healthy.

    But scientists say this does not appear to be true for some flying insects that serve an important purpose. There is growing evidence that these insects are decreasing across the world.

    One researcher looking into the present insect population is Doug Tallamy, a professor at the University of Delaware. He remembers walking through Washington D. C., in the past when it was "alive with insects, especially butterflies". Now, he said, "The flying insects are actually gone." Wilson said this point seemed to be proved during a drive he made last year from Boston to Vermont. He was surprised that, during his trip, he counted only one insect that had hit the car's front window. Several other scientists have carried out similar tests by checking how many insects hit their cars while traveling.

    While researchers admit this method is not scientific, they say it can still help them understand the changing flying insect population. There have not been many studies done on the flying insect populations covering large areas. However, some international research suggests a downward turn. In 2006, a group of studies showed that there had been a 14-percent drop in ladybugs(瓢虫) in the United States and Canada from 1987 to 2006. In Germany, a 2017 study found an 82-percent drop in the number of flying insects compared to levels recorded in 1990.

    After the German study, other countries also started looking into the problem. David Wagner of the University of Connecticut says other evidence leads him to believe the findings of the 2017 study are "clearly not a German thing".

Traveling Tips

    No Smoking

    Federal and State Government Regulations do not allow you to smoke on board express coaches within Australia.

    Luggage Allowance

    As a fare paying customer you are entitled to take 2 pieces of personal luggage. Each must not exceed 75 cm in length, or weigh more than 20kg.

    Excess luggage will be carried at the company's excess luggage rate and depending on space availability may be required to be carried on another coach.

    Luggage Tips

    1) Keep your valuables with you. Money, jewellery, valuable documents, credit cards, keys, medications should be retained by you and not on the coach at meal or transport stops.

    2) Use sturdy, lockable luggage. Do not use plastic bags as these may split during the transit.

    3) Make sure you identify your luggage with a name tag.

    4) Backpacks—stow all items and do not leave mugs, shoes, towels hanging off your backpack as these can get caught in other luggage and cause damage.

    Departure Times

    The time shown on your ticket is the coach departure time. If you are boarding halfway and not at a travel centre or terminal you should be at the pick up point 15 minutes ahead of this time, so you can be comfortably on board by the time the coach is due to leave. If you are boarding at a travel centre or terminal, please arrive at least 20 minutes prior to the published departure time and remember to allow extra time at peak travel times.

    Dress Requirements

    As a courtesy, and so as not to offend fellow travelers, a reasonable standard of clothing and footwear is required.

    "Don't tell anyone". We hear these words when someone tells a secret to us. But it can be hard to keep a secret. We often tend to "spill the beans", even if we regret it later.

    According to Asim Shah, professor in the Menninger Department of Psychiatry and Behavioral Sciences at Baylor College of Medicine, US, keeping a secret may well" become a burden". This is because people often have an "obsessive (强迫性的) and anxious urge to share it with someone".

    An earlier study, led by Anita E. Kelly, a scientist at the University of Notre Dame, US, suggested that keeping a secret could cause stress. People entrusted with secrets can suffer from depression, anxiety, and body aches, reported the Daily Mail.

    But with secrets so often getting out, why do people share them at all? Shah explained that people often feel that it will help them keep a person as a friend. Another reason people share secrets is guilt over keeping it from someone close to them. A sense of distrust can develop when people who are close do not share it with each other." Keeping or sharing secrets often puts people in a position of either gaining or losing the trust of someone." according to Shah.

    He added that talkative people could let secrets slip out. But this doesn't mean that it is a good idea only to share secrets with quiet people. A quiet person may be someone who keeps everything inside. To tell such a person a secret may cause them stress, and make them talk about the secret.

    Shah said that to judge whether to tell someone a secret, you'd better put yourself in their position. Think about how you would feel to be told that you mustn't give the information away. Shah also recommended that if you accidentally give up someone's secret you should come clean about it. Let the person know that their secret isn't so secret anymore.