A study finds that not enough morning light causes teenagers not to get enough sleep at night. “As teenagers spend more time indoors, they miss necessary morning light. Day light is needed to keep the balance of the body’s 24-hour biological system (生物系统), which regulates (调节) body temperature and sleep styles,” reports Dr. Mariana Figueiro. “These teenagers who receive little morning light are going to bed later, getting less sleep and doing badly in tests. They are more likely to fail in their exams.”
In the study, Dr. Figueiro asked 11 students in Grade 8 to wear special glasses to prevent blue morning light from reaching their eyes. At the end of the 5-day study she found that they fell asleep 30 minutes later than usual.
Throughout her research, Dr. Figueiro has been very worried about teenagers going to bed too late. The problem is that today’s schools require teenagers to be in school very early in the morning. These students are likely to miss the morning light because they often go to school before the sun is up or as it’s just rising.
Furthermore (此外), the schools are not likely to provide enough electric light to keep the balance of this biological system. Our biological system is much more sensitive (敏感的) to blue light. Therefore, having lots of light in the classroom does not make sure that there is enough light to keep our biological system balanced.

A week ago, Columbus Middle School asked the parents of their school to choose a sport for their child to play. Here’s some information about the sports.
Sports 1: Basketball
We expect that this will be the most popular of the four sports. So students should sign up (报名) as soon as possible. Students will take a private bus to and from Kwun Tong Sports Park. Each student will have to pay $ 10 each time for the cost of the bus. There will be four basketball courts available for our use with one teacher watching over each game.
Sports 2: Gym
We will use St. Peter’s Park. There are two reasons for choosing this park. First, it is not very busy and crowded before 6:00 p.m. Second, it has lots of trees with plenty of shade. Students must bring along two bottles of water to prevent from being thirsty. All the activities here are free. And there will be a teacher on duty for each activity.
Sports 3: Hiking
Hiking (远足)will be at Kowloon Peak. The activity will start at 2:30 p.m. and finish 90 minutes later. There will be 15 students in each group. And three teachers will be with the students. This sport will cost $ 75 per hour. Students should take plenty of water and sunglasses.
Sports 4: Swimming
The Kowloon City Swimming Centre is a 10-minute walk from our school. Four teachers will go to the pool and watch the students from the poolside. We will only be able to use the pool for one hour (2: 45 p.m. to 3:45 p.m.). Only students skillful at swimming can take up this activity. The pool will have two lifeguards on watch. Girls must wear swimming suits. The cost is $ 15 per visit.