—         exciting news!

    One day, a teacher entered the classroom and told the students they would have a surprise test. After hearing that, all students were seated excitedly and waited for the test to begin soon. Then, the teacher gave the test papers to all students. However, the students were confused(困惑的)to see that there were no questions but just a black dot(点)in the center of the page. The teacher noticed the students' facial expressions and told them, "I want you to write about what you see there."

    The students were still confused but got started with the test. At the end of the class, the teacher took all the answer sheets and started reading each answer in front of all students. All of them described about the black dot and tried to explain its position. After the teacher finished reading, the whole class was silent.

    Then, the teacher began to explain. "Don't worry. I am not going to give you grades for this, but I just want you to think about something. Here everyone focused(聚焦)on the black dot and wrote about it, but no one wrote about the white paper, the same is with our lives. The white paper represents(象征)our whole life and the black spot represents problems in our life."

    Our life is a gift given to us by God, with love and care, and we always have reasons to celebrate-our friends around us , the job that provides us with livelihood , the miracles(奇迹)we see every day. Still we just focus on day to day problems like health issues, lack of money, problems in relationships and so on, but we never see that these problems are very small, compared to everything we have in our lives. So we should try to be happy and live life positively.

    Different from common belief, blue light may not have a strong negative effect as people thought—according to the scientists from the University of Manchester.

    It's known that our body clock measures brightness through melanopsin(黑素蛋白)a specialized light sensitive protein in the eye. So there has been lots of interest in studying the influence of light on the body clock. Researchers changed the make-up of short and long wavelength light, which provided a small difference in brightness as well as changes in color. Findings suggested blue light might be troublesome to our sleep patterns.

    The new research, however, used a different method, since the changes in color may oppose the benefits from reducing the brightness signals detected（探测）by melanopsin. The team used specially designed lighting to change color without changing brightness.

    Findings of the new research showed that blue colors produced weaker effects on the subjects' body clock than equally bright yellow colors. "Our recognition of color comes from the retinal cone cells （视网锥形细胞）, and the blue color signals they supply reduce the influence of light on the body clock," explained the lead researcher. "The research shows the common view that blue light has the strongest effect on the body clock is misguided."

    According to the team, using dim（昏暗的）, cooler lights in the evening and bright warmer lights during the day may be more beneficial to ensure healthy patterns of sleep. Twilight（暮光）is both dimmer and bluer than daylight and the body clock uses both of those features to decide on the proper times to be asleep and awake.

    The findings have important suggestions for the design of lighting and visual displays which aim to promote people's sleep patterns. Present technologies are mostly designed to limit our evening exposure to blue light by changing the screen color of mobile devices. The technology, however, may send the body clock mixed messages. This is because the small changes in brightness they produce come along with colors that are commonly seen during the day. So there's more for the designers to take into Consideration.

    Setting our body clocks in line with our social and work schedules can be good for our health, and using color correctly could be a way to help us better achieve that.