1. I will therefore look for _ additional reason for the change.
2. _ European case study will also be adopted.
3. We decided to take _ average score instead.
4. _ widely-held view is that they are no longer effective.
5. It is _ advantage for them to have _ country- centric viewpoint.
6. The patient was advised to go for _ ECG 
7. This is _ undercooked sweet potato.

Answer
1- an
2-a
3-an
4-a
5-an,a
6-an
7-an