In HIV, what does the "I" stand for?

Around 1590, Dutch spectacle maker Zacharias Janssen is credited with inventing which instrument? Complete the title of Christopher Marlowe's poem published in 1598: "___ and Leander". Which 15th-century German cardinal and philosopher wrote "On Learned Ignorance"? Which Elizabethan poet and courtier wrote the sonnet sequence "Astrophel and Stella"? Sixteen of which unit make an avoirdupois pound? Sixteen tablespoons equal one of which unit? Which unit of time is 1/60 of a minute and until 1960 was defined as 1/86,400 of a mean solar day? In 1605, Part One of which Spanish classic was first published?