题目

New research shows sheep are clever        People often make jokes about how dull sheep are, but new research shows they may be cleverer than we think. Researchers at the University of Cambridge discovered that Welsh mountain sheep have brainpower that equals rodents (啮齿动物). Tests found that the sheep can map the area they live in, and some may even be able to plan ahead. Young fish prefer noisy neighbors        A new study has shown that young fish like to live on reefs with noisy neighbors! Researchers from the universities of Auckland and Bristol found that you某发光点S所发出的两条光线经平面镜反射后形成的光线如图所示，请完成光路图并确定发光点S的位置．