Specifically, we had success predicting the spread of dengue in Brazil at the regional, state and municipality level using these data streams as well as clinical surveillance data and Google search queries that used terms related to the disease. 各位老师好，这是在网上搜到的...
He says he is tired.
He said he was tired.
He said he had been tired.
请问老师这三句话怎么理解？我完全不明白第 1 句和第 2 句。他说自己累，这个说的状态一旦形成不就是过去了吗？不过去就没有说啊~! 怎么会有says呢？
我好像陷入...
The fight for India’s freedom had been won without a battle having ever been fought.请问老师们：(1) 句中的 without 结构不是独立主格，应该是 without 介词短语，是吗？(2) having ever been fought 是现在分词作 a battle 的后置定语，请问为何是“现在分词...
...e's mind, and, such as it was, he tried to convey it to me. Already he had accepted me as his friend; and when I looked at his great, snuff-brown first-mate's hand, with which he brought emphasis to his periods, within six inches of my nose, I wondered if, by any chance, he was as ...
She wouldn't sing it if she hadn't learnt it.脱离语境，上句是否有2种理解呢？真实的或新的吗？章振邦的新编高级语法书上510页，说上句可用unless改写=...unless she had learnt it.我的困惑是：1）上句如果是虚拟语气，怎么可以用unless改...
... that the stream of life would flow on through time in whatever course God had given it。through time是穿过时间的意思吗？in whatever course 的in是按什么方式的意思吗？这本部分的意思是生命之河穿过时间，按上帝给他的方式向前奔流。
I also had to do some community service. It was either that or pay a large fine, but i didn't have any money, so i spent 200 hours gardening in the local park.请问此处为什么用pay这个动词的原形呢?