(时期)period: It indicates any passage of time, great or small. /an extent of time of any length.
(时代)time(s): It refers to a period in history. in ancient times/ in Victoria time
(新时代)epoch: It indicates a long period of time marked by events or development of a particular kind.
The first flight into space marked a new epoch in the history of mankind.
(纪元)era: It refers to a very long period of time marked by a particular feature in a great new era of world revolution
(时期)age: It shows a particular /a fairly definite period in history. the Bronze
Age, Iron Age
3.战斗 (打仗)
fight: It is a bodily struggle (奋斗 斗争)
struggle: An effort of any kind to overcome difficulty.
(战斗) battle: A fight between armed forces.
(战役) campaign: A series of related military operations in a war.
(战争) war: A period of fight between countries or states when
weapons are used and many people are killed.
(对抗) combat: A fight, conflict, controversy.