如图所示，一束光线垂直射到玻璃砖的一个面．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．要求在斜面处标出法线．

阅读短文，下列问题

B

    Jilin Province is located(位于) in China's northeast. It has a long winter with snow that can last for seven months a year. Many people go to Jilin for the Ice Lantern Festival and winter sports.

    Jilin also has many natural and historical attractions, including the famous Mount Changbai. 

    The following is one of the top 10 attractions in Jilin.

    Located in the southeast of Jilin City, Jilin Province, Songhua Lake is one of the most famous artificial (人工的) lakes in China. 

    Covering a total area of 550 square kilometers, the lake has a maximum water capacity (最大蓄水量 ) of 10.8 billion cubic meters. The lake, which looks like a string of pearls, is 200 kilometers in length, 10 kilometers at its widest point, and 75 meters at its deepest point.

    The Songhua Lake consists of nine scenery zones, including Wuhu Island, Wolong Pond, Fengwu Pond, Shilong Wall, Hailang Hill, Shuangfeng Ridge, Luotuo Peak,Qingshan Hill and North Heaven Gate. It is a perfect place for people to visit.

如图是绿色开花植物受精过程、种子、芽和植株结构示意图，请认真观察图示并分析回答下列问题：

     【甲】已而夕阳在山，人影散乱，太守归而宾客从也。树林阴翳，鸣声上下，游人去而禽鸟乐也。然而禽鸟知山林之乐，而不知人之乐；人知从太守游而乐，而不知太守之乐其乐也。醉能同其乐，醒能述以文者，太守也。太守谓谁？庐陵欧阳修也。

     【乙】山故有亭^①，世传以为叔子^②之所游止也。故其屡废而复兴者，由后世慕其名而思其人者多也。

       熙宁元年^③，余友人史君中煇以光禄卿^④来守襄阳。明年，因亭之旧，广而新之，既周以回廊之壮，又大其后轩，使与亭相称。君知名当世，所至有声^⑤，襄人安其政而乐从其游也。因以君之官，名其后轩为光禄堂；又欲纪其事于石，以与叔子、元凯之名并传于久远。君皆不能止也，乃来以记属于予。

     【注释】①亭：这里指岘山亭。②叔子：羊祜，字叔子，西晋著名的政治家、军事家。③熙宁元年：公元1068年。熙宁，宋神宗年号。④光禄卿：主管光禄寺的官员。⑤声：指好的声誉。