如图，①、②表示了细胞的两种生理过程，其中②表示细胞的（　　）

“市井经纪之家……夜市直至三更尽，才五更又复开张。如耍闹去处，通晓不绝……”。材料所反映的现象最早发生在（    ）

声音的三个特性是音调、 ____和 ____；弹吉它时，用力拨琴弦时，琴弦的振幅较大，所以发声的 ____较大 。

下列说法中：
① 若$f\left(x\right)=a{x}^2+\left(2a+b\right)x+2$（其中$x\in 2a-1,a+4$）是偶函数，则实数b=2；
② $f\left(x\right)=\sqrt{2013-x^2}+\sqrt{x^2-2013}$既是奇函数又是偶函数；
③ 函数$f\left(x\right)=\ln \left(x^2-3x-4\right)$的减区间是$\left(\frac{3}{2},+\infty \right)$；
④ 已知$f\left(x\right)$是定义在R上的不恒为零的函数，且对任意的$x,y\in R$都满足
$f\left(x,y\right)=x·f\left(y\right)+y·f\left(x\right)$，则$f\left(x\right)$是奇函数。
其中正确说法的序号是(    )

读短文，将方框里的五个句子还原到短文中。

C

    I'm Mark. I live on a farm. There are some elephants on my farm. They can play soccer and ____. They are very smart. I use them to carry things, sometimes, ____.

    I'm Sue and I'm from India(印度). The Indian people look up to cattle. ____. When you come to India, you can see cattle walking along the streets, and eating fruits and vegetables in the shops.

    Hi, I'm Judy. I live in Australia. My family has three shepherd dogs(牧羊犬).  These dogs are not big but ____. They can run very fast.

    I'm Leo and I have a parrot. Her name is Susan. She is beautiful and interesting. And she can speak, too. When my friends come to my home ____. Susan likes eating carrots. And she likes singing when she feels happy.