【正确答案】这种趋势始于第二次世界大战期间，当时一些国家的政府得出结论：政府向科研机构提出的具体要求通常是无法详尽预见的。

【答案解析】[精解] 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．
句子分析：
一、句子可以拆分为三段：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．
二、句子的结构：
1)主干结构是主句+when 引导的时间状语，when=at that time 当时，那时。
2)第一个that 从句是主句宾语the conclusion 的同位语。
3)that a government wants to make of its scientific establishment 是定语从句中的主语从句
4)cannot generally be foreseen in detail 是宾语从句的谓语。
三、词的处理：
trend 趋势；
came to the conclusion 得出结论；
the specific demands 具体要求；
make of 向……提出；
scientific establishment 科研机构；
in detail 详尽；