题目

阅读理解Recess (课间休息) time has been dropping for many children in America. This drop began the same year the No Child Left Behind Act (NCLB) was passed. The law aimed to make American education system more internationally competitive by introducing achievement goals for schools. And the goals are gauged (评定) by standardized tests in reading and math. If schools missed their achievement goals, they could be in trouble, including loss of funding.It's no surprise that teachers have felt the pressure to make sure students perform well on standardized tests. When educators are f已知玻璃对某种单色光的折射率n=2，现使一束该种单色光沿如图所示方向射到三棱镜的AB面上，最后从棱镜射出．假设光在行进过程中有折射光线存在时不考虑反射问题，则（1）在原图中画出该光束在棱镜中的光路图，（2）求光射出棱镜时的折射角．（结果可用反三角函数表示．）（已知一组可能使用的三角函数近似值sin10°=0.17  sin20°=0.34  sin40°=0.64  sin50°=0.77）