do-gooder

['du:ɡudə]

do-gooder (n.): "a person who seeks to correct social ills in an idealistic, but usually impractical or superficial, way," 1650s (as do-good), in "Zootomia, or Observations on the Present Manners of the English: Briefly Anatomizing the Living by the Dead. With An Usefull Detection of the Mountebanks of Both Sexes," written by Richard Whitlock, a medical doctor. Probably used even then with a taint of impractical idealism. Modern pejorative use seems to have begun on the socialist left, mocking those who were unwilling to take a hard line. OED has this citation, from "The Nation" in 1923:
There is nothing the matter with the United States except ... the parlor socialists, up-lifters, and do-goods.
The form do-gooder appears in American English from 1927, presumably because do-good was no longer felt as sufficiently noun-like. A slightly older word for this was goo-goo.

1. Look, you've typed " do " as'so " , and made nonsense of the whole sentence.: 瞧, 你把do打成了so, 这样一来句子就不通了.

3. The best thing to do when entering unknown territory is smile.: 踏入未知地带最好的对策就是微笑。

5. For what do we live, but to make sport for our neighbours, and laugh at them in our turn?: 我们活着是为了什么？不就是给邻居当笑柄，再反过来笑他们。