1 . Plants Crying in Pain

Try to think about this: you sit down and begin to eat a tomato. Suddenly, the tomato starts to scream (尖叫)! This would never really happen. But a new study shows that plants make sounds when they are stressed.

Scientists in Israel did the study. They used ultrasonic microphones to record (记录) the sounds of tomato plants in boxes. They listened to three groups of plants.

The first two groups made sounds 30 to 50 times every hour. The third group only made the sound once every hour. “When tomatoes are not stressed at all, they are very quiet (安静的),” Lilach Hadany from the study team told CNN.

Scientists believed that animals and insects may listen to the sounds. For example, the sound can tell them that the plant is stressed and not good for laying eggs (产卵) on. When an animal wants to eat plants, it can also use sound to choose which one to eat.

The scientists also listened to other crops such as wheat (小麦) and corn. They also made more sounds when stressed. Scientists said the study can help farmers in the future. They can better take care of the crops by “hearing” how plants feel.

Do potatoes play a small role (角色) on your dinner table? Maybe it’s time to make a big change! Potatoes have become China’s fourth staple food (主食) after rice, wheat and corn. Using potatoes as a staple can make us healthier. They do good to us in many ways.

Potatoes are nutritious (有营养的). They are rich in vitamin C. As we all know, vitamin C can help people keep strong. A potato’s vitamin C is as rich as 10 apples. Potatoes are also low in calories — they don’t have as much calories as wheat and corn have, but they have high-quality protein. These are what people are looking for in a healthy diet (饮食).

Also, potatoes are easy to grow. People can plant them in almost every part of China. They can even grow well on barren land. What’s more, potatoes don’t need much water to grow. China is facing water shortage problems, so potatoes are a good choice.

Many Chinese people think potatoes are vegetables. They cook potatoes along with other things, and the dishes made with potatoes are really delicious. As a staple, potatoes can also be cooked differently. Scientists have tried to make noodles and other staple foods with potatoes, just like how we use rice or wheat. Would you like to try potato noodles? They taste pretty good.

Potatoes have many good points, but it doesn’t mean we can eat them every day. Potatoes have a lot of starch (淀粉). If we eat them a lot and do little exercise, we will get fat. Also, too much fried potato food, such as French fries or potato chips, will be bad for our health.

In a word, we are what we eat. No matter how good the food is, we should eat in a right way, then we’ll look good and healthy.

The students of Class 1, Grade 7 are going hiking (徒步旅行) on their field trip. Hiking is good for people’s health. Many hikers like to hike in the countryside (乡村), forests and mountains (高山).

Just walking for fun is the first kind of hiking. Many people like to hike in city parks or just on the sidewalks.

A hike can take a few hours or weeks. People just need clothes and shoes that are good for the weather. At the beginning, hikers should start with walks that they can do in one day. As you get stronger, you can go an overnight hikes. Later you can go longer than that. You can make your hike last for several days or weeks.

For safety(安全), hikers should hike with someone. It is a good idea to have one or two friends with you. Hikers should also carry a map. It’s useful.

Backpacking is another kind of hiking. People carry food, clothes and other things on their backs in a pack. Backpackers can stay many days in the places where there is no food to buy. They carry what they need on their backs.

Now, put on your hiking shoes and take a hike!

8 . Can you live without meals? Do you like eating breakfast? Someone ever said, “Eat well at breakfast; eat enough at lunch; eat less at supper. “Breakfast is the most important one.

Recently a test was given to people of different ages, from 12 to 80 in the United States. During the experiment (实验), these people were given all kinds of breakfast. And sometimes they got no breakfast at all. If they didn’t have breakfast, they would feel hungry, no energy or power. They could not work well. Their bodies work well when they eat a certain kind of breakfast. The results (结果) show that if people eat breakfast, he will work better.

So eating breakfast is good for our health. When you eat breakfast, food is the most important. It can give us enough energy so that we can work all day. A healthy breakfast could be bread, eggs, milk and fruit. If we eat breakfast before going to school, we will learn more quickly, and listen with more attention to class.

Get up earlier so that you would have enough time for your breakfast. Healthy breakfast can make you smile easily and make your life colorful.

9 . In April 1961, Yuri Gagarin became the first man to travel in space. On July 20, 1969, Neil Armstrong became the first man to walk on the Moon. Some people believe the next step is for humans to visit Mars. It is sure that the first person to walk on Mars will become as Gagarin or Armstrong, and many astronauts would love the chance. But what is space travel really like for the astronauts?

Many astronauts suffer (承受) physical problems, even if they are in space for just a few months. Some of these problems are short-lived; others may be long-lasting. More than two-thirds of all astronauts suffer motion sickness (晕动病) while traveling in space. In space, the body cannot tell up from down and that can make the astronauts feel sick for a few days. More blood and water end up in the face, neck, and chest, resulting in a puff (肿胀) face and an enlarged heart. Being in a weightless environment (失重环境) means that astronauts do not use the muscles (肌 肉) so their muscles gradually get weaker. This, along with the change of blood to the upper body, astronauts lose some of important minerals (矿物质), and then their bones become weaker. As a result, many astronauts can’t walk well for a few days upon their return to Earth. In addition, they have to suffer the radiation (辐射) from the sun. This puts them at a higher risk of serious illness.

Besides the physical difficulties, astronauts who travel for long time may also suffer from psychological stress (压力). Long journeys need astronauts to spend more time inside a spaceship. For example, a round-trip journey to Mars could take about three years. Staying in a small space for such a long period of time is not healthy.

Astronauts—especially those who achieved important “firsts” such as Gagarin and Armstrong—are often seen as exciting adventurers.This may be right, but it’s also worth (值得) remembering the efforts they make to explore our universe.

There are a lot of plants in the world. Plants are very important. This is because plants can make food for us from air, water and sunlight. Animals and man cannot make food from air, water and sunlight. Animals can get their food by eating plants and other animals. Man gets his food by eating plants and animals, too. So animals and man need plants in order to(为了) live. This is why there are so many plants around us.

There are two kinds of plants: flowering plants and non-flowering plants. Almost all the trees around us are flowering plants. You can know some trees from their flowers and fruit. Non-flowering plants do not grow flowers. You cannot see many non-flowering plants around you.

Look carefully at the plants around you, and you can find there are many kinds of plants. Some plants are large and some are small. Most of them are green. Thanks to the plants around us, we can live on earth.