Answer:
The thought of us residing in utter blindness petrified me! or you could use For a long time he could not utter a word, so that the Rhetor had to repeat his question.
Explanation:
1. Therefore
2. All in All
3. However
4. In spite of
5. For example
6. Nevertheless
7. Simply because
8. In addition
9. For instance
10. For this reason
11. Further
12. Given These points
13. Along with
14. Indeed
15. That is
Bonus: Morever