问题 这里为什么不是on？

These hotspots are significant because they allow us to locate key areas for focusing efforts at conversation.雅思听力这句话，为什么是focusing efforts at conservation 而不是 on呢?

问题 But it is left me on my own的理解与分析

But it is left me on my own.left 什么词性啊，为什么接了me? 还有 on my own 是状语成分么？请详细分析，谢谢！

问题 the cost to your health还是the cost on your health

...考卷语篇型填空题里的一句话(There could be an even higher cost on your health.)使用的却是...cost on your health的介词搭配结构。请问老师：介词on和to在上述语境里可以互换吗？

问题 一般过去时Where were you与现在完成时Where have you been的区别

...;  B. have you been   C. did you go   D. have you gone我倾向于选择B（现在“已经回来”了，两人在当面对话）,但是参考答案是A！如果选择A，那么C不是也正确吗？请问如何辨析？谢谢！

问题 介词for使用疑惑？

"Of course, there was no explanation he could give except that he'd gone off with a woman. I suppose he thought she could find that out for herself. That's the sort of chap he was.""What is Mrs. Strickland going to do?""Well, the first thing is to get our proofs. I'm going over to Paris myself.""And...

问题 为什么开头用But if?第三小句为什么直接to be unleashed,是进一步解释说明吗?

But if people instead regard these excess savings as delayed income, then the cash hoard represents stimulus that has not yet gone to work, to be unleashed when the economy fully reopens.

问题 副词的位置

Focus more on 与Focus on sth more. 老师这两个表达都是可以的吧？More focus on sth，这种一般情况下是错误的吧？除非用于倒装, 如：More focus on earnings, less focus on eureka

话题 insist on /upon 后接宾语从句

问题 介词用法

学生反复查看了柯林斯on的42条用法，朗文的49条用法，感觉没有一条释义可解释以下句子或结构中on的用法。   一，An honorary degree was conferred on him.   二 ，congratulate sb on sth       三，Troops advanced on the rebel stronghold.

话题 from now on时态的深入研究

话题 absorbing and reflecting on law

话题 the cost on your health

话题 on the way to do

话题 on the way to doing

话题 solution on/of/for/to