The term “to extend an olive（橄榄） branch” means to make an offer of peace or reconciliation(和好). This term has Biblical（圣经的）origins, coming from the section of the Old Testament that deals with the flood; the sign that the flood is over is an olive branch brought back to the ark(方舟) by a dove. Olive branches were also symbols of peace in Ancient Greece and Rome, and they continue to be used in various works of art that are meant to suggest peace.

    Some people have suggested that the olive was a very deliberate and well-considered choice as a metaphor(比喻）for peace, because olive trees famously take years to mature. War is typically very hard on the trees because people cannot take the time to nurture them and plant new ones. Therefore, the offer of an olive branch would suggest that someone is tired of war, whether it is an actual war or a falling out between friends.

    In Ancient Greek and Roman times, people would offer actual olive branches. In Rome, for example, defeated armies traditionally carried olive branches to indicate that they were giving in, and the Greeks used them into weddings and other ceremonies. In the modern era, the branch is usually metaphorical, rather than actual, not least because the plants can be a bit difficult to obtain.

    Many people agree that peace negotiations at all levels of society are a good idea. Between nations, obviously, it is important to extend an olive branch to ensure mutual safety and to help the world run more smoothly. This act can also be important on a personal level, as resolving conflict and learning to get along with others is viewed as an important life skill in many cultures.

    At some point in their lives, many people will be advised to extend an olive branch to settle a dispute or resolve an issue. Some people believe that it takes an immense amount of courage to take this action, as it often comes with an admission of wrongdoing and regret.

    Getting paid to stay in bed all day sounds pretty good. But what if someone offered you $23,000 to stay in bed for two months? That's the deal that are search team is offering to 24 volunteers.

    Researchers are looking for volunteers to help them study the influences of weightlessness on the human body by spending 60 days lying down. Lying in bed isn't exactly the same as being weightless, but the influences on the human body are similar.

    When astronauts spend a long time in an environment with no gravity(重力), like the International Space Station (ISS),their bodies are affected in many ways. After a couple of months on the ISS, astronauts' hearts don't beat as hard. Their muscles（肌肉）become weaker because they no longer have to work against gravity. Their bones may break more easily. There may also be changes in the astronauts' sleep habits.

    Dr. Arnaud Beck, the researcher in charge of the study, said his goal is to measure the influences of weightlessness, and also to find ways to prevent problems. The study will take 88 days altogether. During the first two weeks the volunteers will be tested to establish(确定) their levels of fitness. Then they will spend 60 days lying in bed with their heads slightly lower than their bodies. They will have to do everything while lying down, including brushing their teeth and going to the bathroom. Dr. Beck said the rule is that they must have at least one shoulder touching the bed at all times. Half of the volunteers in the study will be taking capsules(胶囊) containing special food supplements（增补物）several times a day to see if they help reduce the health problems caused by weightlessness. The last two weeks of the study will be spent trying to let the volunteers recover. Volunteers must be men between the ages of 20 and 45 who are in perfect health. They must be non-smokers.

    The study will take place from September 1^st to November. The first two days are the time for volunteers to sign in.

    Gravity signals that race through the ground at the speed of light could help seismologists(地震学家) get a better handle on the size of large, destructive quakes soon after they hit，a study suggests. The tiny changes in Earth's gravitational field, created when the ground shifts, arrive at earthquake monitoring stations well before earthquake waves.

    “The good thing we can do with these signals is have quick information on the magnitude (震级) of the quake,” says Martin Vaillée, a seismologist at the Paris Institute of Earth Physics.

    Earthquake equipment in China and South Korea picked up gravity signals immediately after the magnitude-9. 1 Tohoku earthquake that destroyed parts of Japan in 2011. The signals appear as tiny accelerations on earthquake-recording equipment, more than a minute before the seismic waves show up.

    “We can look before the earthquake waves arrive,” says Vallée. “If we see nothing, we can say that the quake that made these was maybe large, but not huge. If we see the signals, it means we really have a very big quake. ”

    Had seismologists been monitoring for gravity changes, they might have realized sooner just how big the Tohoku earthquake was. A small increase in an earthquake's magnitude means a large change in the energy released by the quake-and the destruction expected. That information is important for emergency responders as they decide what resources to arrange.

    It'll be a major contribution if gravitational waves can beat down the time needed to know that a big earthquake is big. But much work remains before gravity signals can be considered a reliable tool in the vital minutes after a big quake. A few extra minutes of warning can save lives, particularly in coastal areas where people can flee ahead of an incoming tsunami.

    Five million people visit Grand Canyon in the US every year. For the purpose of helping project Grand Canyon for your fellow visitors and future generations, please follow the guidelines below.

   Camping

    To project the park, camping is allowed only within permitted campgrounds. Permits are required for overnight camping at the North Rim. Advance booking can be received by mail. Please write: Information Center, P.O. Box 129, Grand Canyon, AZ 86023

    Fires

    Because of the extreme fire danger, campfires are not allowed except at Mather and Desert View campgrounds. Collection of firewood is not allowed either.

    Hiking

    Please stay on permitted paths. Otherwise you may destroy desert plants. Pack out what you pack in, so you leave no signs of your visit. It is important to keep in mind that you are in a national park where wildlife exists.

    Weather

    The weather at Grand Canyon can change very quickly. With so much rock, lightning causes a particular danger during sudden summer storms. These storms also frequently bring floods inside valleys, a danger to hikers. Watch the skies and check daily weather reports.

    Wildlife

    Do not feed park wildlife. There have been a few cases at Grand Canyon National Park where deer were purposely shot because they ate plastic bags that left them sick and weak. Hungry deer can be danger and have kicked and bitten visitors at Grand Canyon. Some other animals will also beg and bite. For your own safety and the well-being of the animals, please do not feed wildlife, no matter how gentle they may appear.

    Steven Stein likes to follow garbage trucks. His strange habit makes sense when you consider that he's an environmental scientist who studies how to reduce litter, including things that fall off garbage trucks as they drive down the road. What is even more interesting is that one of Stein's jobs is defending an industry behind the plastic shopping bags.

    Americans use more than 100 billion thin film plastic bags every year. So many end up in tree branches or along highways that a growing number of cities do not allow them at checkouts(收银台). The bags are prohibited in some 90 cities in California, including Los Angeles. Eyeing these headwinds, plastic-bag makers are hiring scientists like Stein to make the case that their products are not as bad for the planet as most people assume.

    Among the bag makers' argument: many cities with bans still allow shoppers to purchase paper bags, which are easily recycled but require more energy to produce and transport. And while plastic bags may be ugly to look at, they represent a small percentage of all garbage on the ground today

    The industry has also taken aim at the product that has appeared as its replacement: reusable shopping bags. The stronger a reusable bag is, the longer its life and the more plastic-bag use it cancels out. However, longer-lasting reusable bags often require more energy to make. One study found that a cotton bag must be used at least 131 times to be better for the planet than plastic.

    Environmentalists don't dispute(质疑) these points. They hope paper bags will be banned someday too and want shoppers to use the same reusable bags for years.

ZOOKEEPER FOR A DAY

    Go wild with an extreme zookeeping experience!

    The Khaki Extreme program is a wild behind-the-scenes zookeeping adventure like no other! The program offers the chance for 11-15 year olds to see first-hand what's involved in looking after amazing wildlife at Australia Zoo.

    During the guided adventures, you'll gain an understanding and appreciation of what's involved in working in one of the world's most popular zoological and conservation areas, and you'll love getting up close with the awesome animals.

    Whether it's helping keepers prepare diets for the animals, cleaning enclosures (围场) for large animals, or making improved activities for Australia Zoo's wildlife — you will have a chance to get involved at grass-roots level.

    After a busy morning getting up close with wildlife, you can enjoy a specially provided lunch while watching the performance in the world-famous Crocoseum. Then you'll also receive a guided behind-the-scenes tour of the Australia Zoo Wildlife Hospital. Here you'll see the kind veterinary (兽医的) team treating sick and injured native wildlife, and you'll learn what you can do to protect Australia's native wild animals.

    Every season is different and so is our Zookeeper for a Day Khaki Extreme program! We'll change the animals and activities each school holiday period to keep it exciting, but with so many great animals on offer, the Khaki Extreme program is always a bunch of fun.

    If reptiles (爬行动物) are more your thing, check our Zookeeper for a Day Khaki Extreme Reptile program. Here you'll have a wild day out with some of Australia Zoo's most scaly (有鳞屑的) and slippery friends. This program may not be available every school holiday period and program dates will be limited. Check the booking page for further details on availability.

    www.australiazoo.com.au

    Open daily 9:00 am—5:00 pm

    Bedtime for some of our animals is 4:30 pm.

    Closed Christmas Day