Nowadays, energy can be obtained through various sources such as oil, coal, natural gas, solar heat, the wind and ocean tides.

　　We have got to study hard, to enlarge our scope of knowledge, to realize our potentials and to pay for our life. （气势恢宏）

　　要想写出如此气势恢宏的句子非用排比不可！

七、 挑战极限原则

　　既然是挑战极限，必然是比较难的，但是并非不可攀！

　　原理：在学生的文章中，很少发现诸如独立主格的句子，其实也很简单，只要花上5分钟的时间看看就可以领会，它就是分词的一种特殊形式，分词要求主语一致，而独立主格则不然。比如：

　　The weather being fine, a large number of people went to climb the Western Hills.

　　Africa is the second largest continent, its size being about three times that of China.