Now too much CO makes the Earth warmer and warmer, and brings bad effect to people. To save our Earth, a new lifestyle called low-carbon life becomes popular. Low carbon means low energy and no waste. It is necessary for everybody to learn to live a low-carbon life.

    To live a low-carbon life, we'd better save as much energy as we can. For example, turn off the lights and TV when you don't use them, use cold water to wash clothes or dishes: take a short shower and try to take a cold one when the weather gets warm: don't do the cooking with electricity.

    To live a low-carbon life, we should eat less meat. Being a vegetarian can help reduce (v)one and a half ton of carbon dioxide a year, but keeping animals for food produces even more carbon dioxide than all the cars do in the world.

    To live a low-carbon life, we should plant more trees. Trees are very important for us. They can not only produce oxygen for us to breathe and keep the air clean. But also take in the harmful gases from the air. To protect trees we should stop people from cuing down trees and plant as many trees as we can.

    If we can keep them a habit in our daily life, the earth will become a safer planet for us to live on.

Liu Yaxuan is totally a homebody. Every weekend, this 14-year-old student from Tsinghua High School watches popular TV dramas and plays with her mobile phone. She hates playing outdoor sports."It's too tiring,"she said.

She is not alone. In recent years, more and more Chinese teenagers are becoming homebodies. A 2013 survey of kids aged 2 to 14 showed about half of them spend less than one hour doing outdoor activities every day.

To some extent, heavy academic pressure (学业压力) caused this situation. Hu Huilan, 12, from Shenzhen Nanshan Language School, is busy with piles of homework and extra classes on weekends."I don't want to get behind,"she said.

Even if this isn't a problem, kids still prefer indoor life. Wang Yidi, 12, from Anhui No. 50 Middle School, often reads Harry Potter, listens to music and surfs the Internet at home."I can do so many things I like at home rather than hang out in smoggy weather,"she said.

But this causes bad health conditions. Chinese teenagers' physical conditions have been dropping for about 28 years, reported a newspaper last year.

The situation for teenagers should be changed. They should spend their free time outdoors even if it just means going to the park or reading a book under the tree. Nice weather, little homework and rich outdoor activities enable them to do that. It helps them stay energetic.

Are you an "I" person or an "E" person? People have talked about it a lot online recently. They are part of a popular personality (性格) test called MBTI.

Everyone's result has four letters. "I" and "E" are the first letters. People are either "I", meaning introverted (内向的), or "E", for extroverted (外向的).

But sometimes introverted people can be outgoing, too. For example, an "I" person will hang out with a group of introverted friends. The person may do things a more "extroverted" person would do. For example, he or she may share their thoughts and feelings with others and ask strangers for directions.

I'm one of these kinds of people. Most of the time, I show an interest in new classmates and friends. I talk with them to show I'm friendly. But honestly, I like being alone and staying quiet.

I have to say, the personality test is just for fun. Everyone's personality is different. Don't let the test tell you who you are.

In this case, I was a bad example. I used to be very interested in my friends' MBTI results. I would get upset if their results didn't match the way I see them.

Soon, I think everyone might have a "personality stamp". For example, "P" people don't like to make plans. On the other hand, "J" people are planners and list-makers. My sister is a "P" person. She never plans. But one day, she was happily making a day-to-day travel plan for the holiday.

"I thought you were a 'P' person," I said to her.

"Do I have to follow what my personality test tells me?" she replied.

"Oh no," I said to myself. "I've taken the result too seriously."

The four letters don't tell you everything about a person. And no one should live according to what four letters tell you.