Love's+Labour's+Lost+Act+4

1. Costard mistakes the letters he delivers. The first is from Don Armando to Jaquenetta: who does Costard think it is from--and to? 2. To whom does Jacquenetta take her mistaken letter? 3. When the four lords enter to read their sonnets, who is last to enter and first to be discovered? What do each of the lords admit? 4. How is Berowne's sonnet discovered?