在西周时代，“姓”和“氏”是两个概念，“姓”表明血统，“氏”则为“姓”的分支。贵族男子的“字”全称有三个汉字：第一个表示长幼行辈（伯、仲、叔、季等），第二字任意，末一字为“父”字。这说明姓氏名字制度在当时最主要的作用（    ）

若方程x²﹣3x﹣1=0的两根为x₁、x₂，则 $\frac{1}{x_1}+\frac{1}{x_2}$的值为____ ．

在放大镜下看一个直角，结果看到的是(      )

增加：在缺词处加一个漏字符号（∧），并在其下面写上该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写上修改后的词。

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。

    One day I went with my dad to a store near our home. Just inside the door stood the most beautiful bicycle I have ever seen. No other kids in our town rode one like it. My dad must have noticed it. Bend down, he asked if I liked the bicycle, who price was a little high. I nodded. To my surprise, he bought it without any hesitate. I felt quite excitedly.

    Later, my father shared with me his experiences of those of his school day. My grandparents had no money for even such the thing as a pencil, and he never dared to ask my grandpa for one. Tears filled with Dad's eyes whatever he recalled his childhood. He said he would do his best get his child what he wanted.

两个相似五边形，一组对应边的长分别为3cm和4.5cm，如果它们的面积之和是78cm²，则这两个五边形面积各是多少cm²？