阅读下面的短文，根据短文内容选择正确答案。
How much do you know about Albert Einstein?
Albert Einstein, born on March 14, 1879 in Germany, was a great scientist in the world. He was strange because he hated haircuts and new clothes. He believed in peace. All his life, he hated war. However, his most famous idea, E = mc², helped create the world's most dangerous weapon (武器). Many people think he was the smartest person in the world. But Einstein said that he thought like a child with many questions and unusual ideas.
What did he like?
Einstein liked learning sailing(帆船运动). He sailed in small boats all his life. Heonce joked, "Sailing is the sport that takes the least energy!”
When Einstein was a child, his mother made him take violin lessons. At first, he didn’t like the violin. But then he learned to love music and became a good violinist.
Later, he said, “Love is the best teacher.”
Why is the sky blue?
In 1910, Einstein asked a question which many children often ask, “Why is the sky blue?”After his careful research, he answered the question like this: “It's because light is made up of many colors including blue. When light travels to Earth, gas particles(气体微粒) spread the blue light all over the sky.”His answer is true in physics.
，在
上是增函数，则（ ）