PTE Listening Practice Test 2

"Today I'd like to discuss one of the most remarkable migrations in the animal kingdom: that of the Arctic tern. Each year, this small seabird travels from its breeding grounds in the Arctic all the way to the Antarctic and back, a round trip of roughly seventy thousand kilometres. Because it experiences two summers each year, one in each hemisphere, the Arctic tern sees more daylight annually than any other creature on Earth. Scientists tracking terns with tiny geolocators have discovered that the birds do not fly in a straight line, but instead follow a zigzag route that takes advantage of prevailing winds, significantly reducing the energy required for the journey. The birds typically stop in the mid-Atlantic for several weeks to feed before continuing south, building up fat reserves for the next long leg of the trip. Researchers believe this migratory behaviour has evolved over millions of years, allowing the species to exploit food-rich waters in both polar regions rather than remaining in one location year-round. Understanding these routes has become increasingly important, since climate change is altering ocean currents and fish distributions that the terns depend on. Conservationists now use this tracking data to identify and protect critical stopover sites along the migration path."

আর্কটিক টার্ন পাখি বছরে প্রায় ৭০,০০০ কিমি ভ্রমণ করে (আর্কটিক থেকে অ্যান্টার্কটিকা)। জিগজ্যাগ পথ বায়ুপ্রবাহ ব্যবহার করে শক্তি সাশ্রয় করে, মধ্য-আটলান্টিকে বিরতি নেয়। জলবায়ু পরিবর্তন তাদের অভিবাসন পথে প্রভাব ফেলছে, সংরক্ষণবিদরা গুরুত্বপূর্ণ স্থান রক্ষা করছেন।

"Increasing noise pollution from roads, shipping and urban development is affecting wildlife in ways researchers are only beginning to understand. Birds in noisy areas have been found to sing at higher pitches and greater volume in order to be heard over background noise, which can make their calls less effective at attracting mates. Marine mammals such as whales rely heavily on sound for communication and navigation, and increased ocean noise from shipping traffic has been linked to changes in their calling patterns and, in some cases, stranding events. Some cities have begun installing noise barriers along major roads and enforcing quieter engine standards for vehicles, aiming to reduce the acoustic impact on nearby parks and green spaces."

"Rooftop gardens are becoming increasingly popular in dense urban areas, and city planners point to a range of benefits. They help insulate buildings, reducing heating costs in winter and cooling costs in summer, which can lower a building's overall energy consumption by a meaningful margin. They also absorb rainwater, easing the burden on stormwater drainage systems during heavy rain and reducing the risk of localised flooding. In addition, rooftop gardens create habitat for pollinators such as bees, which are otherwise scarce in fully paved city centres. Some cities now offer tax incentives to developers who include green roofs in new building designs, recognising these combined environmental and economic benefits."

"As the number of satellites in orbit continues to grow, so does the amount of space debris — discarded rocket stages, defunct satellites, and fragments from past collisions — now orbiting Earth at extremely high speeds. Even a paint fleck travelling at orbital velocity can damage a satellite or spacecraft on impact. Several companies and space agencies have proposed methods for removing debris, including nets, harpoons, and robotic arms designed to capture and safely deorbit defunct satellites. However, progress has been slow, largely because of the enormous cost involved and the absence of clear international agreements on who is responsible for cleaning up debris left by different countries' space programmes."

"Although they appear as thin, solid bands from a distance, the rings of Saturn are composed primarily of countless small particles of ice and rock, ranging in size from tiny grains of dust to boulders as large as a house."