We always think that it's OK for us to leave our plants home during our vacation as plants won't scream like pets, right?

    A recent study done by a group of scientists at the Tel Aviv University has discovered that some plants will scream when they are under stress.

    The research was carried out on tomato plants and tobacco plants by cutting their stems (茎) and depriving (剥夺) them of water. A microphone was placed 10cm away from them. When their stems were cut, the plants started "screaming" between 20 and 100 kilohertz, and the scientists guess that this scream is probably meant to warn other plants nearby.

    When the tomato plants' stems were cut, 25 ultrasonic (超声的) pain sounds were recorded in an hour, and at the same time, 15 ultrasonic pain sounds were recorded from the tobacco plants. When they were deprived of water, the tomato plants recorded even more pain sounds with 35 pain sounds in an hour while the tobacco plants recorded about 11 pain sounds.

    The plants also acted differently to different kinds of stresses. For example, the tobacco plants gave out a stronger "scream" when they were deprived of water than when their stems were cut. But plants that were in no immediate (立刻的) danger gave out less than one ultrasonic sound per hour.

    The group of scientists said that plants are not as quiet as we had always thought, but in fact their voices are so high-pitched that we just can't hear them.

    Last year, another study has found out that plants feel pain when they are touched or hurt and they will give off a terrible smell.

When we are in the wild, we find that water is important for us to live. There are many ways to get some clean water. For example, if there is fire and enough water, the best way is to boil the water. But in many cases, there doesn't seem to be any safe water available.

Can you think of a way of cleaning dirty water by using the sun? In this activity, you will make a "solar still (太阳能蒸馏器)". Let's get started to make pure water (纯净水)!

Imagine walking around a fashion store. You see a beautiful leather bag and want {#blank#}1{#/blank#} it. But in fact, it's made from recycled fruit and food waste. Would you still buy it?

Song Youyang, a 30-year-old material designer, works on developing products. She studied material design at a university in Germany and now lives in China. {#blank#}2{#/blank#} she was designing some new products, she couldn't find any suitable biomaterials (生物材料) to work with. So, she and her team decided to develop {#blank#}3{#/blank#} own new material from fruit waste.

The resulting material {#blank#}4{#/blank#} a lot like leather. It keeps the fruits' texture (质地), sense of touch and nice smell. Song and her team have used this new material to make fashion {#blank#}5{#/blank#} , such as bags, lamps and so on.

The designer thought these products would be {#blank#}6{#/blank#}. But in fact, not many customers have bought them. "Many people have their old ideas about biomaterials," said Song. "They think these materials are too expensive or of {#blank#}7{#/blank#} quality." As a result, it's quite difficult for these materials to become {#blank#}8{#/blank#} used. But Song still believes biomaterials will shape the {#blank#}9{#/blank#}. She and her team will {#blank#}10{#/blank#} working on new types of "green" materials and products.

Besides Song's team, many other fashion companies are {#blank#}11{#/blank#} working towards the same goal. They are showing us that fashion can be environmentally friendly.

Here's a famous doctor's advice. 

●To keep fit, you need to have right food for each meal. Start the day by drinking a glass of water or orange juice. It's not good to have coffee or tea with an empty (空的) stomach. You should know that water is the best drink. 

●For lunch, you'd better not have junk food like hamburgers or French fries. Fish and green vegetables are really right for lunch. They can give you all kinds of nutrients (营养) . 

●If you still feel hungry in the afternoon, eat some fruit or have some nuts (坚果) —they're good for your health. Don't eat too much sweet food such as ice cream and chocolate. It's not good for your teeth. 

●For dinner, have some bread and soup (汤) . Fresh vegetables are also suggested. 

Kindness is important because it can make people feel confident. {#blank#}1{#/blank#} . As a mother, I teach my children through my actions and talks. I believe these ways may help you become kind too. 1. Listen and show interest. 

By listening tosomeone or showing interest inthe talk, you can change someone's life. 2. Show compassion(同情). 

Showing compassion is a great way to show kindness. You can do this by telling them you understand them and care for their words, {#blank#}2{#/blank#} . By doing so, you are having an act of kindness greater than any. 

3. Help others. 

{#blank#}3{#/blank#}. By helping others solve a math problem or giving advice, you are helping other people out. Don't forget to help others when they are in need. 

4. Say thank you. 

A "thank you"can go a very long way and help you do many things, but many people forget it. {#blank#}4{#/blank#} This is very important when meeting people who are serving(服务)you, like your waitress. 

 Summer holidays are usually the most {#blank#}1{#/blank#}(令人兴奋的) time in a year. There are many choices to {#blank#}2{#/blank#}(放松) for people off work. To make your holiday become more{#blank#}3{#/blank#}(令人愉悦的) and {#blank#}4{#/blank#}(有意义的), here is some {#blank#}5{#/blank#}(建议) for you. First, you can go sightseeing around your home town because there are no {#blank#}6{#/blank#}(机会) to go abroad. And it won't cost as much as travelling around the world. Besides, it's a good way to join an extra- curricular course. As we all know, {#blank#}7{#/blank#}(练习) makes perfect. The more you learn after school, the more {#blank#}8{#/blank#}(优秀的) you will become. What's more, the {#blank#}9{#/blank#} (主要的) task of a student is working hard. So do your homework carefully in time and make fewer {#blank#}10{#/blank#}(错误).