Drawing on research into a specific historical event or phenomenon, show how the passage you've chosen makes sense of, or perhaps fails to make sense of its historical subject.
利用对特定历史事件和现象的调查，告诉我你所选的段落如何解释或是无法清楚解释历史事件。
2
Spring designing system provide important parameters for later spring drawing system, spring drawing system construct a picturize Passage for spring designing system.