If you look outside, you probably will see some kind of insect. If your first instinct is to kill it, take a moment to think about all of the benefits insects provide to the environment.

  Entomologists, scientists who study insects, estimate that there are more than 800,000 species of insects found throughout the world. Only a few hundred of these insects are considered harmful. Mosquitoes, for example, are considered harmful. They bite humans and other animals, and their bites can cause skin pain and spread disease. Desert locusts also are considered harmful because they destroy crops causing billions of dollars in damage each year.

  However, the number of helpful insect species far outweighs the number of harmful species. Some insects make up a vital part of the food chain. Many different birds, reptiles, fish and even plants eat insects. There are also about 500 insects that people in various parts of the world eat. These insects are considered delicious food and prized for their high protein, mineral, and vitamin content. Other insects produce valuable commercial products such as silk, wax, and honey.

  Of all the insects, perhaps the most important are those that travel from flower to flower and pollinate(授粉) the plants they visit. Agriculture around the world would be very different without the bees, butterflies, moths, flies and wasps that pollinate many crops. In fact, nearly one-third of the food you eat depends on plants that are pollinated by insects!

  While it is true that some species of insects harm or annoy us, you should not automatically reach for the bug spray when you come across an insect. You may be destroying one of the hundreds of thousands of insects that provides many benefits to human beings.

   B

     Many people have long dreamed of being able to fly around as simply as riding a bicycle.  Yetthe safety and strength of a flying bike was always a big problem.Over the past 10 years, developments in technology have moved the dream of personal flying vehicles closer to reality. Now, two groups of inventors say such vehicles may be available very soon.

      Grant Stapleton from Malloy Aeronautics says the Hoverbike, which is able to get in and out of small spaces very quickly, will be a truly personal flying vehicle.  "It can be moved across continents very quickly because it can be folded and packed," he adds.

      Mr. Stapleton says safety was the company's main concern when developing the Hoverbike. He ays the designers solved the safety issue by using overlapping rotors  (折叠旋翼)  to power the vehicle. The company is testing both a one-third size model and a full-size prototype  (原型)  of the Hoverbike.

     Inventors say their Hoverbike will most likely be used first by the police and emergency rescue teams.

     In New Zealand,  the Martin Aircraft Company is also testing a full-size prototype of its personal flying bike, called Jetpack. It can fly for more than 30 minutes, up t0 1,000 meters high and reach a speed of 74 kilometers per hour.

     Peter Coker is the CEO of Martin Aircraft Company.  He said Jetpack "is built around safety from the start, " In his words, "reliability is the most important part of it.  We have safety built into the actual structure itself, very similar to a Formula One racing car. "

     Jetpack uses a gasoline-powered engine that produces two powerful jet streams.  Mr. Coker says it also has a parachute (降落伞) that can be used should there be an emergency. "It opens at a very low altitude and actually saves both the aircraft and the pilot in an

emergency," he adds.

A

       Visit Australia’s Top End on a Northern Territory camping tour through Kakadu, Katherine Gorge and Litchfield national parks. This five-day tour to the Top End’s three most popular national parks takes you hiking to waterfalls, swimming in rock pools and spotting crocodiles on a private wildlife cruise. Experience the Top End’s unique culture, spend evenings around the campfire and sleep under the stars at private campsites in a traditional Australian bedroll or a permanent safari tent. This small-group tour is limited to 16 people, ensuring a personalized experience with your guide, and operates seasonally from May to November.

Additional Information :

    ●Confirmation will be received at time of booking.

     ●There is a possibility of cancellation after confirming if there are not enough passengers to meet requirements. In the event of this occurring , you will be offered an alternative or full refund.

     ●A moderate amount of walking is involved.

    ●Minimum age is 5 years.

    ●Please restrict luggage to 22 lbs（10 kg）. Excess luggage can be stored at your Darwin accommodation.

     ●Please bring hat, sunscreen, water bottle（1.5 liters）, walking shoes/boots and swimsuit.

     ●Take insect-resisting measures.

     ●All camping equipment provided including sleeping bag, pillow, pillow case, towel and sheet.

It has often been suggested that the ocean, rather than space, is the true final frontier. From the extremely high pressure that threatens human lives to unknown geography that can injure people and machines alike, various things make sending human explorers hazardous. The deepest section of the ocean is the Marianas Trench, which begins at 20,000 feet. It has points where the depth approaches seven miles and the pressure reaches eight tons per square inch. That’s why the Marianas Trench remains largely unexplored to this day.

Even knowing about all of the difficulties, however, some scientists feel the draw of the ocean’s depths. The environment, unfriendly though it may be to man, is friendly to others, allowing for the development of quite a few creatures not found anywhere else on the planet. The first exploration of the Marianas Trench’s floor took place in 1960. Since then, the cost of sending people back has been seen as too great.

The goal, then, has been to find a way to learn about this frontier without risking the lives of explorers. One way that scientists have discovered new information is through the use of sonar. As sonar technology — a sound-based method of determining surroundings — has improved, scientists have been able to get more accurate maps of the ocean’s floor.

Another method of exploration that has become more common in recent years is to use machines that have no people working inside them. These include underwater cameras and robots. The latter have become increasingly common in recent years.

Although most of the robots used so far have been attached to a larger device with people aboard, the day when the robots can move independently may not be far off. As technology is being advanced, it seems quite likely that automatic robots will become more competent ocean floor explorers than humans.

C

Nearly one billion of the world’s people do not have an“adequate (足够的)”supply of water, and most of these people are in the world’s developing nations. The lack of water services is the cause of much disease and illness in the developing nations. Increased demand and greater use of water (caused by population increases) often create the need for extra water treatment because water from new source areas tends to be of lower quality. Water services would be improved if the construction of facilities (设施) were not so costly.

      Water pollution in the developing nations is sometimes caused by overuse of fertilizers and a general lack of pollution prevention laws. Access to good wastewater treatment facilities in these countries is very limited. As a result, water bodies in the developing nations are often open to human and animal waste products. Besides, the waste chemicals of factories are also poured into these water bodies.

       In the developing nations, floods account for about 40 percent of all deaths caused by natural disasters. For example, 3.7 million people were killed in a 1931 flood on China’s Yangtze River. However, floods also carry sediment（沉积物）and nutrients into flood plains. This natural process is important for agricultural production. Programs for flood management should consider and find a way to balance the harmful and beneficial aspects of floods.

      Throughout the developing countries, deforestation (滥伐森林) is being caused by a combination of overpopulation, improper land use practices, and a lack of environmental laws. Soil erosion (侵蚀) is a natural process, but deforestation and other human activities have led to a five times increase in the average levels of sediment carried in the world’s rivers. Too much sediment in rivers can damage ecosystems and fisheries, affecting the people who directly depend on them.

D

The sun is setting on a summer night. At the entrance to a deep, dark cave, a few bats fly out. Then more and more of the small, furry creatures appear. Within a few minutes, a whole river of bats is pouring out of the cave, and they keep coming — millions and millions of them.

       Sound like a scary horror movie? Believe it or not, this scene takes place every night, all summer long, at Bracken Cave in Texas, where 20 million bats fly outside to feed on insects.

      Every March or April, Mexican free-tailed bats migrate up to 1,609 kilometers from their winter home places, like mines, tunnels, hollow trees, and under bridges in Mexico to this cave. Soon after they arrive, each mother gives birth to one baby bat. As many as 500 baby bats live crammed (挤) into one square foot of space, and those bodies create nice warm temperatures to keep them warm and comfortable. With bad sight, how can mother bats recognize their own babies? Their good sense of smell helps them the most.

      When the adult bats leave the cave at night to feed, they eat tons of insects in a single night, including many pests that eat farmers’ crops. And they get rid of mosquitoes, too.

      The cave, quiet in winter, is full of life all summer. The floor of the cave is covered with bugs. Gnats are flying around, and beetles are crawling up your leg when you walk in!

      When twenty million bats fly out of one cave opening, they make a column (柱) so thick that they show up on the radar at the nearby airport. So much for bats being scary!