Leap year occurs every: year 8 years 4 years 2 years

leap year occurs every 4 years.hope this helps

Explanation:

oil! is what i am assuming

mount st. helens in washington erupts, causing a massive avalanche and killing 57 people on this day in 1980. ash from the volcanic eruption fell as far away as minnesota. seismic activity at mount st. helens, which is 96 miles south of seattle, began on march 16.