问题 操作题

如图所示,两条反射光线是同一发光点S发出的光线照射同一平面镜上的反射光线,试确定发光点S的位置

答案

解:第一种作法:先将两条反射光线AB、CD反向延长交于一点S?,再通过平面镜作出S?的对称点S,即为发光点的位置,并连接SA、SC画出入射光线,如图所示:

第二种作法:先过A点垂直镜面作出法线,在法线左侧指向入射点画出入射光线,注意反射角要等于入射角,同理画出反射光线CD的入射光线,两条入射光线的交点S即为发光点的位置,如图所示:

多项选择题 案例分析题
完形填空

II.语言知识及应用(共两节,满分35分)

第一节 完形填空(共10小题;每小题2分,满分20分)

阅读下面短文,掌握其大意,然后从2l~30各题所给的A、B、C和D项中,选出最佳选项,并在答题卡上将该项涂黑。

One evening I made a trip to the grocery store (杂货店). As I   21   the room I noticed a man off to the side with a small cardboard   22   that read something to the effect : “Needing change for a hot meal.”

I also   23   several people passing him by with little more than a glance. He looked to be a traveler and seemed to be very humbled at having to ask of others. I too walked on by, but with a seed of a (n)   24   planted in my mind. I went to the far back of the grocery store where they offered the only thing I could think of that would be   25  . I bought him a couple slices of pizza and immediately went back outside to   26   it to him. I told him that it wasn’t much but it was the   27   think they had that was hot. I smiled   28   and turned to walk away and as I did he smiled back with a deep   29   and let out a very soft “thank you”. That look was worth ten times more to me than what I had been able to offer him, and it was a look I won’t   30  .

21.A.knocked at       B.closed       C.left       D.entered

22.A.sign         B.signal       C.notice       D.advertisement

23.A.inquired      B.noticed     C.begged     D.stared

24.A.dream         B.game     C.idea      D.trick

25.A.cheap          B.hot       C.delicious   D.warm

26.A.show         B.award       C.deliver      D.offer

27.A.only         B.very     C.same     D.exact

28.A.secretly       B.Shyly     C.gently       D.broadly

29.A.shyness        B.curiosity   C.surprise    D.appreciation

30.A.forget          B.forgive     C.treasure    D.Doubt