问题 过去完成时的用法

I ___(lose) my key, so I couldn’t get into my house. But now I ___(find) it.第一空答案是lost,我填的是had lost,我的理解是我过去的过去丢了钥匙，对过去造成影响couldn’t get into my house，请问是已经找到钥匙那对过去的影响也不成立了吗？

问题 地点状语前是否该有介词

老师们，好!when reports came into London Zoo that a wild puma had been spotted forty-five miles south of London .这个句子中forty-five miles做状语前面为什么没介词呢？比如at forty-five miles south……望解惑，谢谢啦！

问题 这道可否理解为错综条件句

Hellen ___ with her class if she had been able to meet all of the course requirement in timeA. will graduate B. would have graduated C. would graduate D. has graduated答案选B，但是想问问可否理解为错综条件句，选c呢?

问题 and,but,so词性和用法问题

经常看到and,but,so放在一个句子的句首大写，那么此时这些词还是作为并列连词连接并列句吗？这些词所在的句子和前面一个句子是并列句吗？

问题 一个复杂句子结构的分析（涉及and where）

Don't forget what to do and where to go you have promised yourself, no matter how difficult or far it is.疑问：1. 为什么用 and 连接啊 where 本身不就是连词么？ 没看懂结构？2. you have promised yourself不应该是在两个 to do 和 to go 前面的么？为什么拿到后...

问题 And with that came increased seasonality 的主语是什么

...,500 B.C.E., the world was coming out of an ice age.FEMALE PROFESSOR: And with that came increased seasonality; that is, the summers became warmer and the winters actually became colder.请问老师，And with that came increased seasonality 的主语是什么？ with that : immediate...

话题 read on and on

话题 both economically and environmentally

话题 travel north and south

话题 and for good reason

话题 at home and abroad

话题 dos and don’ts

话题 not A and B

话题 A and B修饰名词

话题 between A and B