今日练习题为综合推理题，题目如下
The diagram shows, in three column groupings, various divisions of Earth's geological history since its formation approximately 4,600 million years ago. In the leftmost column grouping, the Precambrian eon is subdivided into chronometric eons shown on the far left; but otherwise, in the rest of the graphic, each subsequent column to the right shows the subdivisions of the timeframes to its left. Each of the rightmost two column groupings is a magnification—with additional information—of a portion of the grouping directly to its left.
Fill each blank to create the most accurate statement on the basis of the information provided.
The Miocene epoch spans closest to __1__ of the era of which it is a part.
According to the diagram the beginning of the __2__ marks the onset of a new eon, era, and period in geological history.
1. A 3% B 25% C 85%
2. A Cambrian period B Triassic period C Pliocene epoch D Precambrian eon
正确答案：
B A
解题思路：
读题可知，图中每一纵列的时间轴在左边，单位是Millions of Years，而且越往下，发生的时间越早，越接近上方，其发生的时间距离现在就越近。
第一个答案选25%%u3002Miocene 本身的span是(估算)5到23=18 M ann. Miocene所在的Era是(注意看第二纵列的Title)橘黄色的Cenozoic，其span是0到70= 70 M ann. 所以18/70=0.25左右。
第二个，问的是哪一个的Beginning就是一个eon的开端，同时又是一个Era和一个Period的开端。看图，第一纵列告诉我们只涉及两个Eon，只有一个(天蓝色的Phanerozoic)有细分为Era和Period，所以就选这个天蓝色的打头第一个就是答案。于是第二纵列告诉我们，属于蓝色的第一个应该是Cambrian.
