Answer:
1. The passage mainly discusses the precipitation of rain and snow
It describes the average rainfall in the whole of United States which is said to be approximately thirty-six inches.
Th general formula for calculating the precipitation of snowfall is that ten inches of snow is equal to one inch of precipitation (rainfall)
2. Although one of his ships succeeded in sailing all the way back to Spain past the Cape of Good Hope, Magellan never completed the first circumnavigation of the world and neither did most of his crew.