Can you check these sentences for me please? Thank you.

1) Who were the Druids and what was their role within the Celtic social system? Refer also (or also refer?) to the etymology of their name.
2) When did te bubonic plague strike England and what were the consequences of its spread?
3) What were living conditions for the Jewish communities in 16th-century Venice like?
4) List briefly the main features of the revenge tragedy. Why can Shakespeare' Hamlet be regarded as a revenge tragedy?
5) How does Hamlet plan to avenge his father's murder? What makes him delay his plan of revenge?
6) What are Hamlet's thoughts concerned with in his famous soliloquy "To be or not to be"?
7) What is the "rub" that makes Hamlet delay his action of revenge?
What does the image of the "unknown country from which no traveller comes back" stand for?

1. no need for "also"

2. "the"

3. OK

4. Briefly list ... Shakespeare's [the play's title needs to be in italics]

5. OK

6. delete "concerned with"

7. OK