Answer:
1. quien
2. por las cuales
3. que
4. cuyo
5. la cual
6. quienes
7. por la cual
Step-by-step explanation:
1. The text is talking about a person that's why It is necessary to replace it with the relative pronoun "quien".
2. It is talking about the reasons why so the better option here is "por las cuales".
3. It is introducing another sentence that's why it is necessary to use "que".
4. In this sentence "en la que nivel" is wrong. The best option here would be "cuyo" because the text is talking about a level so It requires a modifier.
5. In this sentence the better option to replace the previus one is "la cual".
6. In this sentence It is necessary a relative pronoun like "quienes" to replace the precident and the vice precident.
7. It is talking about the economic crisis so the better option to replace this sentence would be "por la cual".