从方框中选择正确选项．并将其字母序号写在对话后面的空格内。(方框中有一个选项与对话内容无关)

Celia: Hi Tony! You look upset. What's wrong?
Tony: I failed the exam again. I'm afraid I have to give up my study.
Celia: No, never. If you do that, you will let your parents down.      ____ 
Tony: Yes. I want to practice basketball and become a basketball player like Yao Ming or Kobe.
Celia:    ____ 
Tony: Because it's my dream job. If I am famous, I can make lots of money.
Celia: Money is important.    ____ 
Tony: I know. But I want to hold on to my dream.
Celia: Have you ever talked with your parents?
Tony:   ____  But they don't agree. They want me to be a doctor.
Celia: I think you'd better take your parents'advice.
Tony: Maybe you're right. But why can't 1 make my own decisions?
Celia: Come on, Tony.  ____      After all, your parents have more experience.
Tony: Anyway, I’ll think about it. Thanks for your advice.

我是拼音小能手

刹那间____ 腹部____ 名副其实____ 绘声绘色____ 

细胞质内与细胞呼吸、植物光合作用有关的结构分别是（　　）

已知数列$\left\{a_n\right\}$满足$a_1=0,a_{n+1}=\frac{a_n-\sqrt{3}}{\sqrt{3}{a}_n+1}\left(n\in N\right)$，则$a_{20}$等于(　　)