你好，
1．source 和origin的区别？
我也不是很清楚，楼主可以直接找本英语词典翻阅英语解释，对比即可。
2.强调句型（摘录）
常见到的强调形式，共有以下七类：
⒈用do\does\did + V可表强调
Some people do believe that nuclear power poses a threat to the world peace.
⒉adv或adj可表强调：Never \ only\ Very
This is the very question that deserves careful analysis.
⒊双重否定可表强调
Taking part-time jobs is never without drawbacks.
⒋what引导的主从可表强调
What really matters is cooperation.
⒌倒装可表强调(凡是倒装都可以表示强调)
Little do people take into account the seriousness of this problem.
⒍比较状语从句可表强调
Nothing is more imperative than to learn from the past.
⒎强调句型可表强调 It is \was +被强调部份+ that \ who +原句剩余部份
It is stability that destroys people’s ambition and barricades people’s steps. （
http://baike.baidu.com/view/190776.htm#3 百科）
3. 高考虚拟语气（自己总结）
1. If +从句主语 + 一般过去时动词+其他成分 ，主句主语 + would + 动词原形+其他成分
（eg. If he were you, he would go home. 注意were）
2. If +从句主语 + 过去完成时动词+其他成分 ，主句主语 + would have+ 过去分词+其他成分
（eg. If he had done homework , he wouldn't have been punishehed.)
3. 倒装：当虚拟条件句的谓语动词含有were, should, had时，if可以省略，这时条件从句要用倒装语序，即将were, should, had等词置于句首，这种多用于书面语。
（eg. Were he you, he would go home.
Had he done homework, he wouldn't have been punished.)
我感觉，这三种结构在高考中是非常常见的，可以以结合句子意思和结构进行做题。
但建议楼主对虚拟语句全面理解，不仅是这些结构，这样才能达到做题准确无误
百科：
http://baike.baidu.com/view/26751.htm