请问下这句子结构是什么样的However,itwasn’tuntilthediscoveryofthereactionprinciple,whichwasthekeytospacetravelandsorepresentsoneofthegreatmilestonesinthehistoryofscientificthought,thatrockettechnologywas

Question

请问下这句子 结构是什么样的
However,it wasn’t until the discovery of the reaction principle,which was the key to space travel and so represents one of the great milestones in the history of scientific thought,that rocket technology was able to develop.

Answer 1

不管怎样,直到反作用原理的发现（它是迈向时空旅行的钥匙,所以它意味着科学设想史上伟大的里程碑之一）,火箭技术才得以发展.
首先,句子的主体是“not until.that.”.即“直到.才.”的句型,即句子主体意思为“不管怎样,直到反作用原理的发现,火箭技术才得以发展.”其次,上面括号内的译文是which引导的从句是对“反作用原理的发现”的补充说明.希望可以帮到你.