分析一下新概念英语1Theyhavebeentoldthatrescueoperationsareprogressingsmoothly.为什么不用Theywastold....2However,rescueoperationsareprovingdifficult.proving在这里是动名词作表语吗？3Ifexplosiveareused,vibrat

Question

分析一下新概念英语
1They have been told that rescue operations are progressing smoothly.为什么不用They was told....
2However,rescue operations are proving difficult.proving在这里是动名词作表语吗？
3If explosive are used ,vibrations will cause the roof of the mine to collapse.to collapse是什么成份？
4If they knew how difficult it was to drill though the hard rock ,to drill是什么成分？
5has enabled the men to keep in touch with their closest relatives keep前面为什么加to

Answer 1

1 用have been told表示现在完成时的被动语态.
2 proving是prove的进行时态.
3 to 是动词 cause 的介词,这个句子里 cause to 是动词词组,做谓语,宾语是 the roof of the mine
4 首先,这个句子是不完整的,只有从句没有主句.其次,it 指代的是to drill though the hard rock 这个部分.
5 to 引导的是一个动词不定式,这个不定式做主语,不过,为了避免头重脚轻,有的时候to引导的不定式做主语,会放在句尾.