问题请教：口语重点(delta中一题as example)

请教大家，口语lecture的题型，哪些是应该说的重点内容呢？

for example, delta speaking中track30 mass migration 记录如下：

mass migration: 19th century  move from places to place  all around the world  esp. continents

                          larger scale

eg. Europe to A Aus. Africa; R to central Asia; China to South Asia

new transportation; development of banking and capital     support

free land   other encouragement

lower social and economic classes

motivation: find better life

labor supply  economic development

问题是what happened in MM和原因

应该说那些内容呢？主要是想问一下，eg.中的那些要不要说？都说加组织语言发现来不及。。。

many thx