...uring the day they are still singing. Singing is a costly behaviour and it takes energy. So by increasing their song output, there might be some costs of energy. ”我对其中的Singing is a costly behaviour不理解，behaviour 不是不可数名词吗？它前面怎么可以用不定冠词呢？...
要表示“是否……”，or not 通常要与whether 连用。如：Nadine was undecided whether or not to go to college. 娜丁尚未决定是否去上大学。Whether or not we can go ultimately depends on the weather. 我们是否能去最终取决于天气。Whether it was unwise or not depe...
...finite program of work. Many able students claim that they work in cycles. Whenthey become interested in a topic they work on it intensively for three or four days at a time. On other days they avoid work completely. There are many students who_____.A．do not like being commanded to study acc...
...nable to regard the sea floor as the basic from ofthe crust ofthe earth, with, superimposed upon, it the continents, together with theislands and other features of hte oceans.老师这句话中的,with, superimposed upon ,it the continents, together with theislands and other features ofthe ocea...
It takes about half an hour to get to theairport.It takes courage to speak out against the tide of opinion. It costs a fortune to fly first class. 这三个句子属不属于简单句五大基本句型中的S+Vt+O结构？to do不定式作主语，用it作形式主语？
...tant framework for development and significant progress has been made in anumberofareas. 其中"provided an important framework for development"一句是修饰“Goals"的定语从句吗？如果是，为什么会用成”provided"而不是“providing"
...other has been fastened to it as a means of tugging her along to keep step with the rush of other shoppers.(专四真题选句)老师您好，我想请教您：1.这里的“to keep step with the rush of other shoppers”能否分析为宾补，keep step with 的主语应该是her mother，而tug的...
...中，却用的是单个的过去分词作后置定语：Do you know thenumberof books ordered? 你知道订购了多少书吗? The experience gained will be of great value to us. 取得的经验对我们将很有价值。请问这作何解释？如何理解？谢谢老师！
... in such relaxed surroundings over prolonged small talk; much less do they take them out for dinner, or around on the golf course while they develop a sense of trust and rapport. Rapport to most of us is less important than performance. over的用法教材上说是当....时的意思，但我...
In France,there once lived a man named Louis Pasteur,who was a doctor of science.The thing which occupied his mind was the disease rabies.老师，这边的which，可以填with which，因为我记得be occupied with是固定的搭配吧?
请问老师"have got to"是否有一般疑问及否定形式？例如 I have got to see a doctor.是否有一般疑问句形式 Have I got to see a doctor?或否定形式 I haven't got to see a doctor.还是have got to 只用于口语的陈述句中？