雅思写作：为11月的烤鸭敲响丧钟 oh sorry 警钟(下)

上一期中回顾了2019年过去十个月份中不同小作文题型的分布，较之2018年和2017年的出题情况，可以初步预判流程图和饼图在今年最后两月的出题几率较高。 流程图的讲解已经在上一期中完结，详情可以参考：【雅思写作】为11月的烤鸭敲响丧钟，oh sorry，警钟(上) 。

【一】

先说一说词汇的准确度。饼图中的数字基本是以百分数形式出现的，表示“比例”时，只能使用percentage和proportion两个词，切记不可使用rate和ratio。rate侧重于“率”，通常以“名词+rate”的专有词组形式出现，比如crime rate(犯罪率)，unemployment rate(失业率) 。而ratio指的是the quantitative relation between two amounts，即两者之间的比例，如某大学的男女生比例是1:8。

另外，饼图中必备的动词叫做“占据”、“构成”：account for/ make up/ constitute/ represent，它们可以接百分数(%)作宾语。常见的错误用词是take up和occupy, 你收藏过的很多不负责任的学习资料里会给到这两个词，它们讲到的“占据”指占空间(space)或时间(time)。例如，the two long windows occupied almost the whole wall，这两扇大窗几乎占满了整面墙。

再说一下account for/ make up/ constitute/ represent该如何使用，给大家对比两个句子：

(正确)Females accounted for 45% of the graduates.

(错误)The percentage of females accounted for 45% of the graduates.

可否判断出为何第二个句子是错的呢？记住，一定要确保“部分”(females)和“整体”(the graduates)是同类信息，只有相同性质的信息(females和the graduates都是“人”)，才能谈得上“占据”。因此我们得来一个结论，即account for/ make up/ constitute/ represent，它们的主语一定不是the percentage/proprotion of...。只能是人或事物。

【二】

饼图的写作思路非常复杂多变。思路会因动态饼、静态饼而不同，且饼的个数也会引发思路变化：双饼、三饼、四饼甚至六饼的思路大相径庭。C11T1的静态六饼图得转变成表格选取极值；C10T1的静态双饼会各自成段后再做跨饼的比较；C9T3的动态四饼要排除变量后按ages分段；C11T2的动态双饼则会将6项归为三类。为了让大家轻松一些，我以动态双饼图为例：

The two charts show the main sources of energy in the USA in 1980 and 1990.

一分钟内搞定Introduction： The pie charts illustrate the changes in energy production from five different sources(oil, natural gas, coal, hydroelectric power and nuclear power) for the USA in two different years(1980 and 1990).

思考：如何判断overview中要搞出什么瓜：What was the main source of energy in 1980?What was the main source of energy in 1990?Which produced the least energy in 1980?Which produced the least energy in 1990?Did the amount of energy produced by each source change a lot or just a little between the years?Did all types of energy increased by 1990? 完成思考后，不难生成以下段落：

Overall, oil constituted the main source of energy production in both years, while hydroelectric power produced the least energy. There was a slight decrease in production from oil and natural gas, whereas an increase can be seen in the figure for coal and nuclear power. （总结极值；概括升降）

Body Paragraph 1。其实主体段的任务就是针对overview里的概括去给出details来support your overview，主体段1考虑先拿下oil和hydroelectric power，前者一直是第一大能源，后者始终是老幺。你要做的事情就是描述趋势和数字，并做好比较：

The percentage of energy produced by oil in the USA was 42% in 1980 and this, then, declined to a third(33%) in 1990. The proportion of energy from hydroelectic power, in contrast, remained constant in both years at a mere 5%.

Body Paragraph 2。把余下的杂鱼能源清理掉：Which sources increased? Which sources decreased? What were the percentages for each source? 拷问灵魂的三连问带走全文：The energy generated by natural gas, which was the second largest source of energy in the USA in 1980, fell by 1% to a quarter of all energy produced in 1990. In contrast, production by coal grew from 22% to 27% in 1990, while there was a 5% rise in energy from nuclear power to reach 10% in the second year.

下一期想让我更新什么？可以点菜。作文批改和文书创作也可以托付给我。