Olympia和Olympiad：它们有区别么
The Olympic Games as we know them taday have a long history which goes back to ancient times. Everything started in the Peloponnese, in Greece, some 3000 years ago.
Sports competitions were organised at Olympia and were named after their location, hence their name of Olympic Games. Nobody knows exactly when they began, but the first written mention of the competitions is dated to 776 BC.
Theses Games were held at the same place every four years. This four-year period acquired the name Olympiad, and was used as a date system: time was counted in Olympiads, rather than years.
重点词汇
Peloponnese n. （希腊南部）伯罗奔尼撒半岛
Olympia n. 奥林匹亚，（希腊）伯罗奔尼撒半岛西部的平原
Olympiad n. (四年一次的)奥林匹克世界运动大会, 四年周期