Children now usually sit all day and spend their time in front of the screens. That’s not good for their health and growth. They should play more sports because sports are fun and they are really important for children.

Firstly, playing sports helps children keep healthy. Many children today don’t get enough exercise. This is one of the reasons why they are becoming too heavy. Sports are a great way to get kids moving. If a kid likes soccer and takes part in soccer games just twice a week, he or she will be much stronger than those who never exercise at all.

Another benefit of playing sports is helping kids to accept failure (失败). Of course it is important to win a game, but if children lose a game, and then they can move on and go farther.

In short, sports are one of the key things for children to keep healthy both in body and in mind. Children must play more sports. It’s time to turn off the TV or computer, put down the cell phone and get them moving!

A．

B．

C．

D．

School backpacks have been a hot topic in China recently. Some Chinese parents buy hard cover school back-packs from Japan, although they can be as expensive as 5, 000 yuan, reports Chinese newspaper Urban Express. These backpacks are popular because the hard cover helps hold books in place. This can help kids keep their balance and protect their spines（脊柱）. But in fact, the bags can hardly fit in the students’ desks.

A good backpack is important for children’s health. “It can relieve（减轻pressure from the shoulders,” says Dr. Rob Danoff from the US. He also says students need a backpack that’s made for the child’s size. Cushioned（加垫的）backs and shoulder straps（带子）will help them keep the pain away.

However, the biggest problem for school backpacks is that they are too heavy, noted Hou Weiguang, a doctor in Chengdu. In China, students have many textbooks and exercise books. “The weight makes many kids suffer from side-bending（侧弯的）spines,” Hou said. He suggests that backpack should be no more than 15 percent of a child’s body weight to avoid pain or injury. That means if a student weighs 50 kg, the backpack should be less than 7.5 kg.

Parents need to make sure their kids only carry what they need. Schools and governments need to help too, added Zheng Yongshun, an education official from Hong Kong.

He said schools should offer locker（储物柜）space and shared books so kids can carry fewer books.

According to recent studies, many teenagers are getting just over six hours’ sleep, rather than the nine hours they need. 【小题1】 Lifestyle changes may be the cause, including staying up late to play online games or use social media.

Scientists found a lack （缺乏）of sleep can cause worrying changes in a teenager’s brain. 【小题2】 As a result, the brain is less able to learn because it cannot take in and understand information properly. The teenagers who had less sleep find it more difficult to reach a goal that has been set for them.

Dr. Salem has spent years studying the effects of lack of sleep on teenagers. 【小题3】 For example, he found that the 15-year-old volunteers with less sleep performed no better than a 13-year-old on tests. 【小题4】 If a teenager is studying a foreign language during the daytime, his or her brain needs enough sleep to encode （编码）new words into the long-term memory. Without enough sleep, new words are forgotten.

【小题5】 And now, there is more scientific evidence （证据）to prove just how much sleep matters.