.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.

　　結(jié)構(gòu)分析：句子主干是This trend began during…, when…引導(dǎo)時(shí)間狀語從句, 第一個(gè)that引導(dǎo)同位語從句，表明conclusion的內(nèi)容。第二個(gè)that引導(dǎo)的是修飾demands的定語從句。

　　譯文：這種趨勢始于第二次世界大戰(zhàn)期間，當(dāng)時(shí)一些國家的政府得出結(jié)論：政府向科研機(jī)構(gòu)提出的具體要求，通常是無法詳盡預(yù)見的。