If you use marathon to describe an event or task, you are emphasizing that it takes a long time and is very tiring.
People make marathon journeys to buy glass here.
人们经过漫长而艰辛的旅途到这儿来买玻璃。
marathons
A marathon is a race in which people run a distance of 26 miles, which is about 42 km.
running in his first marathon.
正在跑他的第一次马拉松比赛。