Misc: What is a giant sequoia?

Questions

Born Yaron Cohen, to the dismay of a number of her fellow countrymen, she won which international competition in May 1998?

Born Georgios Panayiotou in England in 1963, by what name is this singer better known?

Which Greek philosopher was appointed tutor to Alexander the Great in 342 B.C.?

Which 1995 film, starring Tom Hanks, used the publicity blurb "Houston, we have a problem."?

In 65 A.D., which Roman emperor forced his former tutor, Seneca the Younger, to commit suicide?