見義勇為 的英文怎麼說?

[1] stand up to injustice
  stand up against injustice[2] step up against unjust acts[3] step up against injustice[4] help those in need[5] help the needy[6] make sure justice is served

stand up to 跟 stand up against 都有勇敢面對的意思，所以 stand up to injustice 就是勇敢面對不正義的事情。

help those in need = help the needy = 幫助需要幫助的人

make sure justice is served = 確認正義有得到伸張

常常可以白話翻譯，例如例句。