题目

One day  61   ant was drinking at a small stream and fell in.  62   (face) with the trouble, she tried her best to reach the side, but made no progress at all. The poor   63   (tire) ant was still bravely making all   64   (effort) when a dove saw her. Moved by her determination and perseverance, the bird threw her a blade(片)of grass,  65   supported her like a raft（木筏）, and thus the ant reached the bank again. While she was resting and drying    66  (she) in the grass, she   67  (hear) a man come near. He was walking along barefooted   68  a gun 20．根据要求作图：（1）根据平面镜成像特点，在图1中作出物体AB在平面镜MN中所成的像．（2）如图2所示，一束与水平面成30°夹角的太阳光经平面镜反射后竖直射入井中，在图中画出反射光线和平面镜的位置．（3）如图3所示，一束光线垂直射到玻璃砖的一个面上，请你作出这束光线进入玻璃砖内的径迹和从斜面离开玻璃砖后的大致径迹．（4）如图4，请画出从光源S发出的三条光线，经透镜折射后的传播方向．