Passage: The collection, in 240,000 words, consists of more than 70 prose, written by Gao during 1980 to 2003, on the natural conditions, social customs and history of the Sub-Sahara Africa. Gao worked in Africa for more than seven years.
What event has already finished? What event has begun but has not finished? What will happen in the future? What happened before the collection was written? What was happening before the collection was written? What is happening since the collection was written? What will happen after the collection was written?