句子拆分
拆分点：从属连词、介词、标点符号
This trend began ∥during the Second World War， ∥ when several governments came to the conclusion ∥that the specific demands ∥that a government wants to make of its scientific establishment cannot generally be foreseen ∥in detail
2、句子结构
找谓语动词(began， came， wants， cannot be foreseen)
找连词(when， that， that)
前面没有从属连词的动词即为主句的谓语动词
确定主从句
主句：This trend began during the Second World War ;
从句：定语从句when several governments came to the conclusion修饰the Second World War，本从句嵌套着一个二级从句即同位语从句that the specific demands cannot generally be foreseen in detail修饰conclusion和一个三级从句that引导的定语从句that a government wants to make of its scientific establishment修饰demands。
3、解析
during the Second World War(介词短语做状语)when several governments came to the conclusion that the specific demands that a government wants to make of its scientific establishment cannot generally be foreseen in detail (做定语修饰)the Second World War ;that the specific demands cannot
