Acronym Soup: GBH&KB?

Questions

at the f-1 grand prix race which killed aryton senna, which other driver suffered the same cruel fate?

the top ranking title in sumo wrestling is known as?

what are the 3 types of swords used in olympic fencing (in alphabetical order, no commas)?

who was the only undefeated heavyweight boxer?

how many victories did rocky marciano score in his professional career?