Answer:
Of the above events, the event which happened first in Romeo and Juliet is:
Friar Laurence gives Juliet a potion.
Step-by-step explanation:
In the four events listed above, Friar Laurence gives Juliet a potion happens first. It then proceeds with the other events. After consuming potion Juliet appeared that she is dead and then she is buried in the Capulet Tomb. Simultaneously, Romeo does not receive the letter and he is unaware of the death of Juliet.