Misc: In 1990 US Ambassador tells---------- , US won't take sides in Iraq-Kuwait dispute. ?

Questions

In what profession is a 'ruderal?

In what sport do the participants compete in the "grand nationals"?

In what sport is a 'chukka'?

In what sport was Eddie Rickenbacker a top contender before WW II?

In what year did einstein cry the word "photon"?