Misc: Who wrote the opera Pagliacci?

Questions

Dinosaurs live in the Mesozoic Era, which is divided into three periods Two of these are Jurassic and Cretaceous What is the third?

How long ago did dinosaurs die out?

Which American President ordered the dropping of the first atomic bomb?

Who has been in power in Cuba since declaring the country a socialist nation over 30 years ago?

Which British Prime Minister said "You've never had it so good" and spoke of the "wind of change"?