Составьте 6 вопросов по пунктам:
1) Общий вопрос
2)Альтернативный вопрос
3)К любому члену предложения кроме подлежащего
4)К подлежащему
5)Разделительный вопрос
6)Разделительный вопрос

And finally, they have had an enduring effect on the world = 1st paragraph, the last sentence

* General Question:

Have they had an enduring effect on the world?

* Alternative Question:

Have they had an enduring effect or a short-term effect on the world?

* Special Question:

What kind of effect have they had?

* Question to the Subject:

What has had an enduring effect?

* Tag Question:

They have had an enduring effect, haven't they?

!!!! Второй tag вопрос невозможен, тк одна грамматическая основа тут: 1 подлежащее + 1 сказуемое))