以下事例能体现“舍小家，为大家”精神的有(　　)
①三峡移民②为街道整齐美观某单位拆掉副楼③有些住户在街道内存放杂物、自行车等④为单位集体利益偷税漏税

阅读下面短文, 从短文后各题所给的四个选项(A、B、C、D)中, 选出可以填入空白处的最佳选项。

    One evening I was going back from a supermarket. As I 1my car, I noticed that some person came and stood beside me. He was homeless. I 2that he will ask me for money, but he did not do that. He only said: “Your car is very 3.”

    After several moments of 4, I replied: “Thanks.” And then the inner(内心的) voice 5to me, “Ask him if he needs help.” After a short 6 I asked him if he needed any help. His respond was7, I will never forget those simple three words “Don't we all?”

    It was a true 8 to me. I needed help, just as those 9. I had money and a place to sleep, but I 10 needed help. Then I opened my wallet and gave him enough11 to get him to have a shelter for a day.

    12I understood that no matter how much money, achievements, luxury(奢侈)things do we have, we all need help. And on the other hand, no matter howpoor you are, how many 13 problems you have, you still might offer your help to others, you still might be giving. 14 it's just a nice word, it can be 15 to other person.

    Maybe that man was just a homeless stranger, but to me he was 16that. Maybe he was a man sent to 17me that there is one thing, among all other18, which is very important and cannot be 19for every person. Actually, it is a true 20 and it is called Giving.

在代数式$\frac{2}{3}$x，$\frac{1}{x}$，$\frac{2}{3}$xy²，$\frac{3}{x+4}$，$\frac{2x^2+5}{2x}$，x²﹣$\frac{x}{\mathrm{\pi }}$中，分式共有（　　）