函数y=Asin（ωx+φ）（A＞0，ω＞0，|φ|＜$\frac{\mathrm{\pi }}{2}$）的部分图象如图所示，则函数的解析式为____ 

用N_A表示阿伏加德罗常数的值．下列叙述正确的是（   ）

    Do you know what the White House is? Perhaps some of you do，while others don't.

    The White House is a house in Washington. The president of the U.S.A. lives in it. It's really white. But do you know why the White House is white? The story happened in 1812. That year England was at war with America. The British army got to Washington and set the president's house on fire. In 1814，in order to hide the marks of the fire，the stone walls of the president's house were painted white and it has been the “White House” ever since.