为了探究机械能守恒定律，岳口高中的金金设计了如图7－9－14甲所示的实验装置，并提供了如下的实验器材：

A．小车

B．钩码

C．一端带滑轮的木板

D．细线

E．电火花计时器

F．纸带

G．毫米刻度尺

H．低压交流电源

I．220 V的交流电源

图7－9－14

增加：在缺词处加一个漏字符号（∧），并在此符号下面写出该加的词。

删除：把多余的词用斜线（＼）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1).每处错误及其修改均仅限一词；

2).只允许修改10处，多者（从第11处起）不计分。

    Are you afraid of delivering a speech before people?I can well remember his first speech which was titled A Real Test in My Life at the age of 9!You can't imagine how terrible shy I was the moment I thought of that—with so many eyes fixed in me.I have no choice but prepare for it,though.When a real moment came,I stood on the platform with my legs trembled and my mind blank.Although it was hard for me to find myself back,but I made it!From then on,I gradually turned out to be a great speakers without any fear of talking.

①AD⊥BC;②CF⊥AE;

③∠1=∠2;④AB+BD=DE,

其中正确的结论有(   )

“中国人民站起来了，是人类历史上极其光辉灿烂的一章，震惊了东亚和世界，促进世界民族解放运动发展。”与之相关的史实是（   ）