天空為何藍色

　　我們看到的天空，經常是蔚藍色的，特別是一場大雨之後，天空更是幽藍得像一泓秋水，令人心曠神怡，躍躍欲飛。天空為什麼是蔚藍色的呢？

　　大氣本身是無色的。天空的藍色是大氣分子、冰晶、水滴等和陽光共同創作的圖景。

　　陽光進入大氣時，波長較長的色光，如紅光，透射力大，能透過大氣射向地面；而波長短的紫、藍、青色光，碰到大氣分子、冰晶、水滴等時，就很容易發生散射現象。被散射了的紫、藍、青色光佈滿天空，就使天空呈現出一片蔚藍了。

resource from: http://gfans.org/psas-list/zh_TW/why_sky_is_blue.html

The Most Important Part of the Body

My mother used to ask me what the most important part of the body is. Through the years I would take a guess at what I thought was the correct answer. When I was younger, I thought sound was very important to us as humans, so I said, 'My ears, Mommy.' She said, 'No. Many people are deaf. But you keep thinking about it and I will ask you gain soon.'

Several years passed before she asked me again. Since making my first attempt, I had contemplated the correct answer. So this time I told her, 'Mommy, sight is very important to everybody, so it must be our eyes'. She looked at me and told me, 'You are learning fast, but the answer is not correct because there are many people who are blind.

'Stumped again, I continued my quest for knowledge and over the years, Mother asked me a couple more times and always her answer was, 'No. But you are getting smarter every year, my child.'

Then last year, my grandpa died. Everybody was hurt. Everybody was crying. Even my father cried. I remember that especially because it was only the second time I saw him cry.

My Mom looked at me when it was our turn to say our final good-bye to Grandpa. She asked me, 'Do you know the most important body part yet, my dear?' I was shocked when she asked me this now. I always thought this was a game between her and me. She saw the confusion on my face and told me, 'This question is very important. It shows that you have really lived in your life. For every body part you gave me in the past, I have told you it was wrong and I have given you an example why. But today is the day you need to learn this important lesson.

She looked down at me as only a mother can. I saw her eyes well up with tears. She said, 'My dear, the most important body part is your shoulder.' I asked, 'Is it because it holds up your head?' She replied, 'No, it is because it can hold the head of a friend or a loved one when they cry. Everybody needs a shoulder to cry on sometime in life, My dear. I only hope that you have enough love and friends that you will always have a shoulder to cry on when you need it.'

Then and there, I knew the most important body part is not a selfish one. It is sympathetic to the pain of others.

People will forget what you said.......
People will forget what you did........
But people will NEVER forget how you made them feel.......