It is saying their illusions of hope.
Yes, it seems to be an alternative, in some situations acceptable, but eccentric and not neutral spelling of this word. It accents the fact that "ea" here are two separate vowels rather than a diphthong: that is the function of the trema (the two dots).
In practice it's not used much, because it's not really necessary: it does not distinguish it from any other word, and trema is not easy to find on English keyboards: so there is no need.
Answer:
Which has a fascinating history
Explanation:
The best adverb clause which would complete the sentence is given above. This is because, the sentence is talking about Mexico as a country in which Oscar was born in. The country has a fascinating history going by its rich culture and traditions of the people living in it.
They demonstrated that if a government does not fulfill citizen`s expectations and it`s considered to be unsatisfactory, citizens have the right, the obligation and also the power to change this form of government in order to be sure that their rights are protected.
