EBC is not a misspelling of the alphabet but the abbreviation of the Everest Base Camp.
Toward the EBC we walked along the Khumbu Glacier. This is a huge glacier and we could clearly see the crevasses, lakes and caves of it. At the EBC we could see the 'valley' where the climbers start to climb toward the Everest peak.
Walking 9km and 500m high difference is not easy around the altitude of 5000m so I was quite exhausted. (Just to compare: On sea level I can walk 40km with 2000m high difference in 10 hours without any problem. I mean I am tired at the end but definitely not exhausted.) So I decided to skip the Kalapatthar hike next day as I did not want to push too far.