1 . Even though one out of three American children live within a mile of their schools, almost not half of those students often bike or walk to class, scientists report. Children who live in the South, in country areas, or who have college-educated parents, are among those least likely to bike or walk to school, which is reported in the American Journal of Preventive Medicine.

Sarah Martin and her workmates at the US Centers for Disease Control and Prevention (CDC) studied materials from more than 7,000 children between 9 and 15 years of age. They found that almost 35 percent of the children lived within one mile of their schools. Children between 11 and 13 years old were more likely to walk or bike than 9-year-olds. Children whose parents had a high school education were more likely to ride a bike or walk than children with college-educated parents.

“The majority of children are missing an opportunity to increase daily physical activity,” Martin said in a prepared statement. According to the CDC, nearly one in five (18.8 percent) children between 6 and 11 years old are overweight. Increased daily physical activity is one of the methods the CDC gives to help deal with the problem among children.

According to Martin, there are all kinds of reasons why children in city areas might be more likely to bike or walk to school. They pointed out the fact that if schools are in places where there are fewer safe sidewalks, the students will be less likely to ride or walk to school. The students should try to ride or walk to school as much as possible and parents are advised to pay great attention to their children’s health.

3 . Shake Shack is a new kind of restaurant becoming more popular in the U.S. The restaurants are not “fast food.” They are known as “fast casual”.

Observers say Americans want more choices and fresh food when choosing where and what to eat. This trend is one reason why the fast food restaurant McDonald's has struggled financially.

McDonald's is one of the best-known restaurants in the U.S. and even around the world. Their ads say “I’m loving it.” But in the last quarter of 2014, McDonald's net income dropped by about $300 million. Worldwide sales dropped for the eighth month and even more than expected.

Bonnie Riggs is a restaurant expert. She says one reason Americans like fast casual food is because it's new. They are creative, they are innovative, they are something different and we like to try new things.

Ms. Riggs says Americans made 61 billion visits to restaurants last year. Three out of four visits were to fast food restaurants, like McDonald's. Fast casual is still a small percentage of restaurant visits. She says it's “growing quickly” because they meet consumers' needs.

“They know it’s being prepared while they wait, it's fresh, uh, fresh ingredients, quality food, good tasting food at reasonable and affordable prices.”

Many Americans still like their fast food, Ms. Riggs says, they just are not going as often. And, she says, some people buy prepared foods at stores and take them home to eat. Others like to cook at home.

4 . If you’re taking a high school chemistry class, you’re likely to spend some time in your school’s science laboratory. Although the lab work is fun, you have to observe the safety rules if you don’t want to hurt yourself or your lab partner.

The first rule is to become familiar with your lab assignment(任务) before you start working with it. This means reading everything the teacher has written down and asking questions if you don’t understand an instruction.

Do not try to work alone. If your partner is absent, let you teacher know so he can assign another student to work with you. And don’t do any other experiments other than what you have been assigned. Keep your hands away from your skin, face, eyes and mouth when you have been working with dangerous chemicals.

You will be working with fire in the lab with an alcohol lamp(酒精灯). Use gloves when handling hot lab equipment. If you have long hair, pull it back in a ponytail and roll up long sleeves. Don’t put paper, chemicals, lab equipment or any part of your body in the flame.

When you use a sharp instrument, treat it with care. Do not point it at yourself or any of your fellow classmates during the experiment.

I will share a true story that happened a couple of days ago to you. One of my classmate bought a bag of snacks from a food store. A few roommates were then invited to enjoy snacks. Unluckily, all of them got poisoned and had a stomachache with our faces pale. They were quick sent to a nearby hospital. Doctors examine them and gave them some medicine. They were out of dangerous soon before taking the medicine. This accident should make us to realize the seriousness of the food safety. I strongly suggest that the whole society pays more attention to this problem.

8 . One student took a box of chicken to class. Another carried on a cell phone _________ , and still another whistled loudly every time the _________ turned his back. Reform school? No. College.

More and more, professors say, they are coming across _________ students in their classrooms. Many of today’s young scholars(学者) arrive late, leave_________, talk loud or take care of personal _________ such as paying bills during class.

Why are the students behaving badly?

“Because they can,” said a student of University of North Texas. “A lot of the time, the professors let them get _________ with it. ”

Some educators say it is time to bring politeness back to their classrooms—and even _________ taking some of the blame for bad behavior. They say that rude students are by no means the majority but that one of them can ruin an entire _________.

People are _________ when they learn that impolite behavior is becoming more and more common in __________ education, says Dr. Gerald Amanda, a counselor at City College of San Francisco. They __________ some high school students to misbehave but think those who get to __________ will behave more politely.

Dr. Amanda believes that society in __________ has become more tolerant(容忍的) of rude behavior and __________ people in power, including professors, no longer __________ standards for __________. That leads to a growing imprudence(轻率行为) __________ some college students. “There’s a great __________ of bad behavior in the world around them, and young people see it and __________ disrespect,” said Dr. Amanda, __________ that sometimes students have no idea that they are being rude.

10 . In a great many cities, hundreds of people ride bicycles to work everyday. In New York City, some bike riders have even formed a group called Bike for a Better City. They declare that if more people rode bicycles to work, there would be fewer automobiles(汽车) in the downtown part of the city and so less dirty air from car engines. For several years this group has been trying to get the city government to help bicycle riders. For example, they want the city to draw special lanes(通道) for bicycles only on some of the main streets, because when bicycle riders must use the same lanes as cars, there are accidents. Bike for a Better city feels that if there were special lanes more people would use bikes.

But no bicycles lanes have been drawn. Not everyone thinks it is a good idea—they say it will slow traffic. Some store owners on the main streets don't like the idea—they say that if there is less traffic, they will have less business.

The city government has not yet decided what to do. It wants to keep everyone happy. On weekends, Central Park—the largest place of open ground in New York—is closed to cars, and the roads may be used by bicycles only. But Bike for a Better City says that this is not enough and keeps fighting to get bicycle lanes downtown.