根据短文内容，从A、B、C、D四个选项中选择正确答案填空。

    Children often  1 this game. They play it like this: Six 2 stand in a row(排) 3 the class. They put their hands 4 their backs(背), so you can't see their hands. The teacher gives one of them 5 rubber. The rubber goes 6 one student to another -- first one way, then the other. They must keep their hands behind their backs. The other students in the class keep their eyes    7. They can't look.

    Then the teacher says: “Stop and put your hands  8 you now.” Now the other students 9 their eyes, and guess who has the rubber. They ask questions like: “Li Lei, is it in  10 right hand?” They can have only five guesses.

阅读下面的材料，按要求作文。

    某人迎着太阳的方向行走。

    他回头对自己的影子说：“讨厌的东西，你怎么老是跟我纠缠不休，以致妨碍我前进呢？”

    “这难道能怪我吗？”影子回答说，“如果你一心向前走而不回头看的话，试问我又能妨碍你什么呢？”

根据你对上述材料的理解，自选角度，写一篇600—800字的文章。

【注意】①题目自拟，立意自定；②除诗歌外，问题自选；③不得抄袭、套作；④文中不得出现你所在学校的校名，以及教职工、同学和本人的真实姓名

在“探究凸透镜成像规律”的实验中，当烛焰、凸透镜、光屏处于如图所示的位置时，恰能在光屏上得到一个清晰的像．利用这一成像原理可以制成  (    )

经过每两点都能画一条直线，如果有3个点最多能画几条直线？4个点、5个点……呢？画一画，数一数，再填表．

你能找到其中的规律吗？