What is a gap through a mountain range, like Donner, called?

In tennis, what is a game tied at 40-40 called? A game was rained out at which enclosed Houston ballpark in 1976 because heavy rain flooded the surrounding area? A gamma-ray burst that was briefly visible to the naked eye in 2008 took place at a distance of 7.5 billion what? A gandy dancer works on what all the livelong day? What would the Argentine gaucho be called in Texas? Which word names both a gazebo and an outdoor newsstand? Which 1841 ballet has been called "the Hamlet of dance"? A Geiger counter is used primarily to measure what?