一道SAT的IS语法题,

1.present messages on subjects as diverse as ……
as diverse as 补充说明subjects,as ……as 成对出现的,
类似的有as many as 1 million people ,为了体现“人多”的意思,才用 as many as这种结构.
2,A选项仅用一个as来举例说明,没有这种表达方式.
如果加上such,即“……,such as astronomy,……”,我认为是可以的.
再问： as有这种用法啊，就是想问是不是一定要加逗号，For instance: large carnivores, as the bear or lion. 谢啦！