阅读理解

    The winter holidays(假期)were here last ! It was Nami's job to make a gift for everyone in family．She did it every year.

    Grandma loves flowers．So Nami drew a picture of flowers for her grandma．Grandpa loves cakes．So Nami made her grandpa a strawberry cake．Cousin Miko loves elephants．So Nami wrote her cousin an elephant story．Uncle Yuri collects coins(收集硬币)．So Nami made her uncle a large clay(陶土)coin．

Nami didn't know what to make for Aunt Hoshi! She didn't know what was special to her aunt．Nami went to find it out．

    First，Nami saw that Aunt Hoshi had a photo of a baseball player in her room．Next．Nami saw Aunt Hoshi's socks．They had small pictures of baseballs on them．Then，Nami saw Aunt Hoshi watching baseball on TV Nami knew what to do．

    At last．it was time for Nami to give the gifts．Everyone was happy when they saw their gifts．Aunt Hoshi jumped(跳)up when she got her gift．

    "Let's play baseball !"she called．Then the family went out and played late into the night．

根据材料内容选择最佳答案。

下列实例中，利用大气压工作的是 (     )

民间剪纸是劳动人民为了满足自身精神生活的需要而创造，并广为流传的一种艺术样式，它生存于劳动者深厚的生活土壤中，体现了人类艺术最基本的审美观念和精神品质，具有鲜明的艺术特色和生活情趣。

由该段文字可知，剪纸艺术的产生主要是为了满足（     ）

已知椭圆$\frac{x^2}{a^2}+\frac{y^2}{b^2}=1\left(a>b>0\right)$的离心率$e=\frac{1}{2}$，右焦点为$F\left(c,0\right)$，方程$a{x}^2+bx-c=0$的两个实根$x_1,x_2$，则点$P\left(x_1,x_2\right)$（   ）