1 . Scientists have reported that the sea ice in Antarctica (南极) is at a record low level. Antarctica is a great, icy land, surrounded (围绕) by the huge Southern Ocean. The ice in Antarctica doesn’t just cover the land. There’s also a large area of sea ice on the ocean’s surface.

Every year, the sea ice at the South Pole goes through a cycle. In the summer, the huge sea ice melts (融化) to its smallest point. Over the colder winter months, the sea ice grows and grows until it covers a wide area. Usually, the sea ice covers the greatest area around September 23, as winter ends at the South Pole.

Scientists have been measuring the area of the sea ice in Antarctica since 1979. For most of this time, Antarctica has seemed to be almost unaffected by the changing weather conditions experienced in other parts of the globe. That began to change around 2016. Now, for several years, the area of Antartica’s sea ice has been shrinking.

This year, the US National Snow and Ice Data Centre (NSIDC) reported that Antartica’s sea ice covered its greatest area on September 10 — almost two weeks earlier than normal. And the sea ice was at a new record low-not just by a little bit, but by a lot.

The last time Antartica’s low sea ice set a record at the end of winter was in 1986. And this year, there’s about 398, 000 square miles less sea ice than in 1986.

Scientists are still trying to understand what is driving the change in Antarctica. One likely direct cause for the change is the rising temperatures of the world’s oceans. Ted Scambos, a research scientist at the University of Colorado, says Antarctica’s ice levels have always changed some, but the sharp loss this year is “pointing towards warmer ocean conditions around the continent.”

The new low record has concerned the scientists. Scientists are working hard to better understand Antarctica. They don’t know yet if this is just a short-term problem, or part of a long-term shift (转变) towards less sea ice in Antarctica.

2 . Flash floods can strike without warning. They can hit when you’re hiking in a river valley, walking through a canyon, or even simply driving to a remote destination. You can minimize your risk by knowing how to prepare for the worst and how to escape when a flood begins.     1    

Before heading out, check the weather report, look at any flood warnings and take them seriously.     2     Dr Steven Kugath, an outdoor recreation professor, notes that when people plan to travel a long way for a hike or canyon exploration, they often feel that they must follow through with the activity even if the weather isn’t promising. The smart thing to do is cancel the activity or move it to a safer location.

Be careful of any visual signs of danger and your surroundings while walking or hiking in a tight space.     3     Besides, always know where you are and where the nearest escape routes can be found in the event of sudden flooding.

What if, despite your preparations, you find yourself stuck in a dangerous place when flooding begins? Move to higher ground immediately, away from rivers and streams. If the situation is urgent, leave behind your possessions.     4     If you find yourself being carried away by powerful flood waters, fight as hard as you can to get to a tall tree, a street light or anything sturdy (结实) that you can hold onto until help arrives.

    5     Currents can be deceptive (误导的), and shallow, fast moving water can knock you off your feet. Moreover, don’t swim through fast-flowing water — you may get swept away or struck by an object in the water.

4 . In a world-record effort to help save a valuable sea creature, Australian scientists have released hundreds of baby seahorses into the wild. The tiny seahorses are endangered, and the scientists hope the new seahorses will help their numbers grow.

Seahorses get their name because they look a bit like horses. They aren’t great swimmers, even though they’re fish. They often use their tails to hold onto something in the water. They mostly live in warm, shallow waters around the world. They are often found in coral reefs, in beds of seagrass, and areas where rivers empty into the sea. Seahorses form an important part of the ocean’s food chain. They eat tiny sea creatures and are eaten by bigger sea animals.

Many kinds of seahorses are often threatened by the human actions. Sometimes they’re caught and sold as pets. They are also caught by accident when people are trying to catch other fish.

To begin the project, scientists collected three pregnant seahorses in January. Those seahorses were brought back to the aquarium (水族馆) in Sydney. After the babies were born, the scientists kept them there for five months, feeding the baby seahorses shrimps (小虾) to help them grow strong. Scientist Mitchell Brennan says, “They don’t have a stomach, so they have to eat constantly.”

About a month before the young seahorses were released, the scientists created eight underwater “hotels” for them. The hotels look like cages, providing a safe place for the seahorses to develop. Putting the hotels into the sea early allowed the cages to be covered with small sea life that can help provide food for the seahorses.

This is the fifth time the scientists have released seahorses into the area, and this time was a record. Around 380 seahorses were released. The researchers put tiny tags (标记) under the skin of many of the seahorses to help track them in the future.

6 . “Is there going to be a flood?” asked Daniel. He looked nervously at his dad and mom. They both looked worried. Dad was completely wet and dirty. He and some other men in town had spent the morning piling bags of sand on top of the levee (防洪堤) along the river. For years the levee had kept the Mississippi from flooding its banks. After three straight days of rain, though, the water grew higher and higher. If the levee broke, Daniel’s neighborhood would be flooded for sure.

“We’ll be fine,” Dad placed a reassuring hand on Daniel’s shoulder. Outside, lightning flashed, followed by distant thunder. “Just in case,” said Dad. “I think we should start moving some things to Uncle Mike’s house.” Uncle Mike lived farther away from the river on higher ground. “And we’ll take everything we need to cook and eat upstairs,” he said, “like camping out in our own house.”

By nightfall, everything the family needed had been moved upstairs. Dad had taken their new couch and TV to Uncle Mike’s. Daniel helped his dad tie a fishing boat to the front (门廊). “Just in case,” said Dad.

Lying in bed that night, Daniel tossed and turned. He could hear the heavy rain beating on the roof. “Everything will be all right,” he said to himself just before falling asleep.

Several hours later, the sound of sirens (警报器) woke Daniel from a sound sleep. He sat straight up in bed, his heart pounding. In rushed Mom ,“Get dressed, Daniel! The levee just broke! We’ re leaving. We have no other choice.”

A few minutes later they all got into the fishing boat, leaving behind just about everything they owned. Daniel asked, “We’re going to lose everything, aren’t we?”

“No, not everything”, said Mom, pulling him close. We’ll always have each other.”

“That’s right,” said Dad. “We may lose the house, but we can always rebuild it. We can’t ever lose our home, though, because home is us.”

7 . The area in front of Janet and Jeffrey Crouch’s house in Columbia, Maryland, does not look usual for their neighbourhood. That is because the Crouches do not have a grass lawn(草坪). Instead, they have some small trees and many native plants.

In recent years, support for replacing lawns with native plants has been increasing in the US. It can be costly to keep a lawn looking good and green. But the Crouches had to spend much more money for the right not to have one.

People living in a house next to them complained to their homeowner’s association, or HOA. HOAs can make rules about the plants that homeowners in a neighbourhood are permitted to grow. Many HOAs require grass lawns. The HOA ordered the Crouches to pull out their native plants and put in grass. However, they refused. “We knew we were doing things that were beneficial for the environment, ” said Janet Crouch.

Lawns are called environmental dead zones in part because they provide no food or shelter for wildlife. They also do not support pollinators like birds, bees, and butterflies. Bee populations have been getting smaller in North America and may be getting smaller around the world.

There are other reasons that lawns are bad for the environment. They require a lot of water and chemicals. Large amounts of water can remove nutrients from the soil. After the water removes the nutrients, people buy even more chemicals to put on their lawns. Scientists say some of these chemicals might cause cancer and other health problems. There are over 16million hectares of grass lawns in the US. That means lawns use more water than any other irrigated(灌溉)crop in the country.

The Crouches’ battle against their HOA took three years. They say they spent $60, 000 fighting to keep their natural garden. They won. Because of their efforts, the state of Maryland passed a law that lets people grow native plants instead of grass, no matter what their HOA wants.