1 . “A moth (飞蛾) to a flame” is often used to indicate an inescapable attraction, yet it is a strange example of animal behavior that continues to confuse people today. Scientists have raised a number of theories over the years to explain why. One holds that insects flying at night are following their nature to fly toward the brightest spot in their field of vision, which they mistake for the sky. Another suggests that insects are trying to warm themselves with the heat produced by the light. The most popular theory, though, is that insects are confusing lights with the moon or other celestial bodies (天体) that they normally use to navigate (导航).

To find out the real reason, the team carried out a first set of experiments in an insect flight area. The researchers used eight high-speed infrared (红外线) cameras equipped with motion-capture technologies to track 30 insects from three moth and two dragonfly species. They also flew lab-raised insects from six different insect orders that were too small for motion-capture technology, including fruit flies and honeybees, to make sure different insects all showed similar responses to light. Working with co-author Pablo Allen of the Council on International Educational Exchange in Monteverde, Costa Rica, the researchers put heavy cameras, lights and tripods in two field sites to gather behavioral data from insects in the wild.

The team was able to confirm that insects were not beelining to the light but rather circling it as they tilted (倾斜) in an attempt to turn their backs toward it. This behavior, known as a “dorsal light response”, normally helps insects to remain in an unchanging path of flight that is properly lined to the horizon (地平线). Artificial light that arrives from a point source causes them to fly in unpredictable patterns as they try to turn their backs to what they are mistaking for the sky.

Now research might have finally solved the mystery mentioned first: artificial light confuses insects’ ability to turn themselves to the horizon, confusing their sense of what is up and down and causing them to fly in circles.

3 . The Chinese paddlefish (白鲟) living in the Yangtze River was declared extinct (灭绝的), according to a paper from Chinese experts at the Yangtze River Fisheries Research Institute. Wei Qiwei, an author of the paper, says that the fish has not been seen in the wild since 2003, nor do artificially bred (人工繁殖) individuals exist.

The Chinese paddlefish is one of the world’s largest freshwater fishes, which can grow up to 7 metres long. People call it “the Giant Panda of Rivers” because it is rare and native to China under first-level national protection, and its ancestors date back to more than 100 million years ago.

From the middle of last century, the population of the Chinese paddlefish declined rapidly due to overfishing, habitat degradation (毁坏) and pollution. The construction of Gezhou Dam in 198l on the Yangtze River also created a barrier to the migrating (迁徙) fish, contributing to the sharp decline of it.

Ministry of Agriculture and Rural Affairs of the People’s Republic of China announced a 10-year fishing ban along key areas of the Yangtze River to protect biodiversity in the country’s longest waterway. It started to come into effect this year.

4 . Hundreds of dead migrating (迁徙) songbirds covered the ground like a carpet on Thursday in Chicago.

Nearly 1,000 songbirds died throughout the night after crashing into the glass of the McCormick Place Lakeside Center due to a deadly combination of excellent migratory conditions, rain, and the low building’s lighting and window-lined walls, according to bird experts.

Window hits are a problem in almost every major city in the United States. Birds cannot see transparent (透明的) or reflecting glass and are unaware that it is a dangerous block. They rush for plants or bushes they see through windows or reflected in them, killing themselves in the process.

Night-migrating birds depend on the stars for direction. Building lights both attract and confuse them, resulting in window hits or birds flying around the lights until they die of exhaustion, a phenomenon known as deadly light attraction.

According to Stan Temple, a retired bird expert from University of Wisconsin-Madison, conditions were ideal for a big wave of songbird southern migration over Chicago on Wednesday evening. “You had all these birds that were just eager to set out, but they’ve been held up with this unusual September and October with temperatures way above normal,” Temple said.

To avoid irregular air movements and predators (捕食者), little songbirds graze to absorb energy during the day and travel at night. They’ve been waiting for north winds to push them south, but September’s unusually warm south winds left the birds in a holding position here, according to Temple. A wind moved south on Wednesday evening, offering a good chance, and millions of birds took to the air.

“Pre-dawn rain forced the birds to fly low, and they found McCormick Place’s lights on,” said David Willard, a manager at the Chicago Field Museum.

According to Ann a Pidgeon, a bird biologist at the University of Wisconsin-Madison, window hits and deadly light attraction are simply avoidable. Building managers can simply decrease their lights, and building designers can create windows with bird-friendly marks in the glass. People can also add screens, paint their windows, or put stickers on the glass.

5 . A houseplant is pretty to look at and brings fresh air to your home. Besides, looking after a plant will give you something more to do and care about. Let’s look at the four best houseplants you can grow.

Australian Pine A perfect “living decoration” to add in your house, it is good to look at and has a comforting feel. It can also serve as the perfect Christmas tree. It grows around 10 feet tall indoors. Remember that it requires plenty of light and fresh air. Otherwise, it becomes weak and an easy target for mites (螨虫).	Dracaena The green and yellow pattern on its leaves looks great. It can grow to be around 10 feet tall. Just make sure you keep the soil surface dry between your watering periods because it gets influenced by too much water. Also, having this plant around a dog can be dangerous. It can be poisonous to dogs if they eat it.
Grape Ivy If you want something off the ceiling (天花板), this houseplant is the one for you. It’s a climbing plant, and it will make for a beautiful hanging basket decoration. The plant is full of life wherever it is hung. It needs to be kept wet in all its parts for good growth.	Peperomia It is little in size, with long leaves. It adds energy to your living room and creates a comforting environment. As it’s not a very tall plant, you needn’t worry about how much space it will take up. The plant likes a dry surface of the soil.

So what are you for? Choose the one that attracts you most, and give your home a wonderful addition.

Last weekend, I took part in a forest clean-up activity. It was organized by Green Hope, an organization devoted to protecting forests.起初，我不想参加，    1    but then I thought, “What if nobody goes?”

Our team leader, Joe, took us to a forest outside the city. I was sad to find rubbish everywhere.     2    There was a “No littering” sign at the entrance to the forest, but that didn’t stop people from throwing their rubbish on the ground. Joe divided us into two groups:    3     one group cleaned up the north side of the forest, and the other the south side. After several hours’ work,看到森林比以前看起来要干净些，我们很开心    4    It was absolutely worth our effort!

There will be another clean-up activity in the greenbelt next Saturday. You can call Joe and sign up    5     if you would like to help. Everyone who takes part in the activity will receive a medal. I’ll join you too if I have time.

Earthquakes are one of the most destructive natural disasters. They can happen just about anywhere. Earthquakes cannot be stopped,     1     your chances of survival are much better if you know what     2     (do) when an earthquake strikes.

If you are in     3     building, drop, cover, and hold on. This     4     (be) the national standard for earthquake safety in the United States. The advice is to get next     5     a strong piece of furniture (家具) so that if a wall falls, it will create something     6     (call) the “triangle of life” to help you survive. Use your     7     (hand) and arms to protect your vital areas like your head and neck. Do not move     8     (immediate) unless it is safe to do so.

Remember that aftershocks are possible at any time and are     9     (likely) after a bigger earthquake. Take good care of     10     (you) when you leave the building.