Getting electricity has always been a problem for the 173 people living in Nuevo Saposoa, a small village in Peru, South America. However, things went from bad to worse in March 2015 after heavy rains damaged the only power cables in the area. The villagers were forced to use oil lamps, which are not only expensive but also dangerous because of the harmful gases they produce.

    Luckily, researchers at the University of Technology (UT) in Lima, Peru heard about their problem and found a wonderful solution. They made a lamp that can be powered by plants and soil, both of which can be easily found in the Amazonian rainforest where the village lies. The lamp takes energy from a plant growing in a wooden box and uses it to light up an LED light bulb.

While that may sound amazing and even impossible, the science behind the ides is quite simple. As plants create their food (using the sun's energy, water and chemicals from the soil), they also produce waste which they return to the soil. Tiny animals in the soil eat this waste and they produce electrons – the building blocks of electrical energy. The UT team put special sticks inside the soil to capture the energy and keep it in the lamp's batteries for later use. The researchers say a single charge can power a 50-watt Led light for two hours - enough time for local villagers to get their evening work done.

The university gave ten Plant Lamps to the villagers of Nuevo Saposoa in October 2015. So far, they have been a huge success! Elmer Ramirez, the UT professor who invented the lamp, believes the Plant Lamp could help improve the lives of many people, especially small rainforest communities, 42% of whom have no electricity.

    Rik-rrork. That's the sound made by frogs singing at night. You might have thought the noises were just the musical sounds of ure. You probably didn't realize that you were listening to frogs' communicating with one another. These familiar sounds are not random(随意的) but are actually meaningful to frogs.

Being Heard but Not Seen

    Frogs are good at being heard but not seen. These animals have several characters that protect them n predators (捕食者 ). One is their size. Most frogs are small, which helps them hide easily. Many frogs have coloring that allows them to hide in their environment, making it difficult for predators to find them. In addition, most frogs are active at night. So it is difficult for most animals to see them in the dark.

Small but Loud

    Frogs call to tell other frogs where they are. Their voices can be very loud. But when frogs feel the footsteps of a larger animal, they become silent.

    Many of the world's frogs live in rain forests, where there are many different animals calling to their own species (物种 ) in their own ways. Frogs need to call loudly enough to be heard through the noise in order to find other frogs.

Singing with Purpose

      Peter Narins is a scientist who studies how frogs call to one another. He has learned that frogs use their calls to help them tell friend from enemy. They sing the same notes at the same volume (音量 ) each time they call. In addition, Narins has found that frogs of the same species always sing the same patterns (模式 ). These patterns are like a code that is different from other animals' calls and difficult for others to copy. Narins also observed that timing plays a role in frog calls. Many frogs call only at a certain time of night.

More Work to Do

    Scientists want to better understand the purpose of frog calls. Studies continue to explore the details of frogs' unique communication. Being heard but not seen is one way frogs stay safe. The idea that they have found a way to survive in a dangerous world is simply amazing.

    We each have memory(记忆力).That's why we can still remember things after a long time. Some people have very good memories and they can easily learn many things by heart, but some people can only remember things when they say or do them again and again. Many of the great men of the world have got surprising memories.

    A good memory is a good help in learning a language. Everybody learns his mother language when he is a small child. He hears the sounds, remember them and then he learns to speak. Some children are living with their parents in foreign countries. They can learn two languages as easily as one because they hear, remember and speak two languages every day. In school it is not easy to learn a foreign language because the students have so little time for it, and they are busy with other subjects, too. But your memory will become better and better when you do more and more exercise.

Do you know Tianshui, a big city along the ancient Siłk Road? It is one of the {#blank#}1{#/blank#} (最古老的) cities in Gansu Province. So people {#blank#}2{#/blank#} (通常地) visit Tianshui for its history and culture. Things have {#blank#}3{#/blank#} (改变) these days, however. More and more people are traveling there for its spicy hot pot(麻辣烫). According to Trip.com, bookings for hotels and attractions in Tianshui have risen {#blank#}4{#/blank#} (四十) percent from a year ago.

In early February, a student posted a video of the spicy hot pot on social media. So far, the video has quickly deceived 1,000,000 likes. Many people said that they wanted to taste the food {#blank#}5{#/blank#} (他们自己).

What makes the food special in Tianshui? That's all thanks to the seasonings (佐料). {#blank#}6{#/blank#} (蔬菜) and meat are cooked with a mix of peppercorns and red pepper oil. The red pepper is grown in Tianshui's Gangu County (甘谷县). The {#blank#}7{#/blank#} (气候) there makes the pepper look bright red and taste great. This gives the hot pot an unusual look and flavor.

The city's increasing popularity has excited the {#blank#}8{#/blank#} (本地的) government. They hope to follow the examples of Zibo and Harbin and {#blank#}9{#/blank#} (发展) the city. Since March 11, they have offered two new bus services to take tourists from train stations to dining places. Also, a food festival was {#blank#}10{#/blank#} (举办) to show the delicious food. They hope to make tourists feel at home.

Hello! My name is Linda Green. I'm a girl. This is my notebook. It's a yellow notebook. How do you 1 it? N-O-T-E-B-O-O-K. That is my schoolbag. My pencil box, a dictionary and a watch are 2 it. My pencil box is red. Three 3 are in it. Look! That is my dictionary. It is 4 English dictionary. It is blue. What color is the watch? It is brown. It's nice. An ID card is in 5 schoolbag, too. It isn't my ID card.6 is on my desk. It's Mike's. His 7 is on it. I will (将会)8 him. His phone number is 8372 - 9810. Oh! What is that? It is a key. Maybe it is Mrs. White's. She 9 a key yesterday. Mrs. White is my English teacher. She has a daughter and a son. Her daughter is Sally. Her 10 is Bob. They are in my middle school, too.