阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式（最多限填三个单词）填空。

    An ant was walking by a river. She looked at the river and said to herself, “____ nice and cool this water looks! I must drink some of it.” But ____ she was drinking, she slipped(滑倒) into the river.

    Luckily a bird was sitting in the tree. The bird quickly used his mouth ____(cut) a leaf from the tree. He dropped the leaf into the river near the ant.

    The ant climbed onto the leaf, and the wind blew the leaf to the bank. And the ant ____(save).

     “Thank you!”shouted the ant, ____ her low voice. But her voice was ____ low that the bird couldn't hear it.

    After a few days, the bird was building his nest. Suddenly a bird catcher ____(careful) took out his nest(网). He quietly walked towards the branch where the bird was sitting.

    The ant saw this, and ran quickly to bite the ____(man) leg. “Ouch” The pain in his leg made the man drop his nest. The bird heard the noise and ____ (fly) away.

    The bird never knew how the little ant helped. ____ the ant was happy that she was able to do something for the bird.

阅读下面的文字，根据要求作文。

    有个教授做过一个实验，12年前，他要求他的学生进入一个宽敞的大礼堂，并自由找座位坐下。反复几次后，教授发现有的学生总爱坐前排，有的则盲目随意，四处都坐，还有一些人似乎特别钟情后面的座位。教授分别记下他们的名字。10年后，教授的追踪调查结果显示：爱坐前排的学生中，成功的比例高出其他两类学生很多。

    要求：全面理解材料，但可以从一个侧面、一个角度构思作文。自主确定立意，确定文体，确定标题；不要脱离材料内容或其含意范围作文，不要套作，不得抄袭。不少于800字。

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$P\left(x_1,x_2\right)$（   ）

有人说绿色植物是“生命之母”，她为大多数生物提供（　　）

①物质    ②能量    ③氧气    ④二氧化碳     ⑤水．