We spoke to three students from around the world about different national holidays．There are different customs (习俗) for each festival．

Tan Xiaodong.15．Hong Kong, China

    “It'll be Chinese New Year soon．Before it we'll clean the house and decorate(装饰) it for good luck．Every shop is going to close for a few days and we'll go out a lot to celebrate in the streets．We might go and see the lion and dragon dances in the city center．I love this festival．”

    Wendy, 16, Sydney, Australia

    “Australia Day is on 26th January and it's an important holiday here．We always have a Monday off, so we celebrate for three days．My parents and I go to the countryside for a picnic and friends always come over．Many people go to beach parties or street parties and there's lots of music and dancing．What fun!”

    Amy, 14, New York, the USA

    “The first Thanksgiving Day was hundreds years ago when Europeans who came to America thanked God for his help．It's still a very important day for families to be together．This year we're going to visit my parents and we'll eat a delicious meal of turkey．Thanksgiving Day is on the fourth Thursday in November every year．”

    Have you ever been in the situation when you really didn't believe what someone was saying? Perhaps they were saying “yes” but their heads were shaking “no”. The difference between the words people say and our understanding of what they are saying comes from body language. By knowing more signs of body language, you can more easily understand other people, and more effectively communicate with them. Movements, gestures, and facial expressions all say that something is going on. What's more, the way we talk, walk, sit and stand all give messages to people. As you watch others, confident people will stand still with shoulders back, give slow and clear speech and always give eye contact. Otherwise, the person seems to have little confidence. If a person speaks to you with his body turning away from you, arms crossed or very small facial expressions, this person is giving his “dead ears”. He usually doesn't listen to you. And it's crucial to know when people are lying. Some of the typical signs that a person is lying include: A person gives little or no eye contact, or there may be fast eye movements. Hand or fingers are in front of his or her mouth when speaking. His skin changes in color, red in face or neck area. Voice changes, etc. However, one size does not fit all. When you watch others, you need to try to guess what they are saying or guess what is going on, but it is also important to recognize that body language may vary between individuals, and between different cultures and nationalities. Understand the signs that you are reading, and have a conversation more easily with people around you.

    A city without cars would be very strange, right? But Venice is such a city.

    Venice is in the northeast of Italy. It wasn't built on land, like Beijing or Shanghai, but on more than 110 islands. Seawater is everywhere around the city.

    Even so, travel isn't difficult. The waterways have always been the best ways to get around. There are 117 waterways and more than 400 bridges that can guide you where you want to go. People in Venice move from place to place by boat. They like to enjoy the scenery and cool summer nights while taking boat trips. They can talk to other people as they go along.

    Venice grew out of small islands in saltwater lakes when some Italians escaped from a war more than 1,500 years ago, and built homes there.

    Water makes the city special, but it is also a big problem.

    Once, people used too much underground water. This made the city get lower little by little. Now the city has gone down by 23 centimeters. Another problem is the rising seawater. The temperature has risen over the years. This has made the ice of the Arctic Ocean (北冰洋) melt (融化).

    Every year, high waters hit the city in autumn and winter. When a lot of water comes, more than half of the city is underwater.

    Scientists are trying different ways to stop the city from getting even lower.

    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.

Are you a fan of spending your lunch breaks in a park? Or do you walk your dog in a park? Well, we have good news: spending just 20 minutes in a park every day will make you happier and less stressed.

New studies have suggested the benefits of spending time in parks. Researcher Mary Carol Hunter said," For lowering levels of the stress, you should spend 20 minutes sitting or walking in a place that provides you with a sense of nature. You don't have to travel to the wild lands. Getting out of an office block and sitting next to a tree can be enough."

A study from University of Alabama found people who visited their local urban parks felt happier. Researcher Hon Yuen sai," We did not find levels of physical activity are related to improved emotional well- being(幸福; 健康). Instead, we found time spent in the park is related to improved emotional well- being." The results are perhaps unsurprising— many studies have stressed the benefits of nature on a person's mental health. Therefore, nature- based activities can contribute to decreasing stress level.

King's College London researchers found being outdoors, seeing trees, hearing birdsong, and feeling in contact with nature were related with higher levels of mental well- being. Another research suggested that children growing up with greener surroundings have 55% less risk of developing mental diseases.

All of these studies mention the need for designing greener cities for the future and protecting our existing parks." There is increasing pressure on green space in cities," said Gavin Jearan, co- author of the urban parks study.

"I am worried because developers look to replace green space with tall buildings. The challenge facing cities is that there is increasing evidence about the value of city parks but we continue to see the disappearing of these spaces."