根据上述结构，给刚刚列举的三道题目中的第一题列出下列提纲：

       原创范例（21题）：

       Introduction: A few reasons are thought to contribute to such phenomenon of a longer life expectancy than before.

       Main body 1: First of all, availability of basic health care makes people live longer.

       eg. More doctors and medicine for common diseases readily available

       Main body 2: Moreover, advances in medicine enable people to live a longer life.

       eg. development of vaccines against some diseases and flus to prolong patients' lives.

       Main body 3: Last but not least, increasing awareness of health makes people live longer.

       eg. regular exercise and change of health-related habits.

       原创范例（168题）：

       Introduction: Several factors are thought to be the essential to lead to this phenomenon that an increasing number of students choose to further their education abroad instead of at home, three of which are most significant.

       Main body 1: First of all, studying abroad enables the students to pursue a program that is not available in their home country.

       eg. learning US accounting system

       Main body 2: Moreover, studying overseas is a good way to enhance their competitive edge in the future job market.

       eg. developing a western critical mind

       Main body 3: Last but not least, students can have access to a new language via pursuing education in a foreign country.

       eg. learning English in the USA

       通过上述结构的介绍，考生可以自行扩展第三题，模仿原创范例，写一个提纲。从上面提纲我们不难发现，在写此类文章过程中，要使文章结构上有逻辑的话，必须掌握表示列举关系和因果关系的连词，先列举如下:

       列举Enumeration：

       第一项，首先： in the first place, firstly, initially, first of all, to begin with, to start with, first and foremost

       第二项，此外： second, secondly, in the second place, also, besides, in addition, moreover, furthermore

       第三项，最后： third, thirdly, in the third place, last but not least, finally, eventually

       因果Cause and effect：

       原因： because, as, since, for, because of, due to, on account of, as a result of, stemming from

       结果： as a result, consequently, therefore, thus, hence

       只有在掌握了表示此类关系的连词的基础上，考生才能自如地运用之前所列举的结构，连贯逻辑的表达。值得一提的是，在最近的考题中，描述解释型的题目出现的几率相对较低。但考生在考前还是需要全面复习，掌握此种问题模式和对应的文章结构，才能在考试中胸有成竹。下一系列中，朗阁海外考试研究中心将为大家介绍新托福独立写作目前最常出现的问题模式：二选一型，并为大家介绍其对应的文章结构。

（来源：无忧雅思网）