关于SC comparison的问题！！求救！og上和Ron大神讲的咋不一样呀

creamysh

OG17: 758题
Pricesat the producer level are only 1.3% higher now than a year ago....

正确答案给的是the sentence as written makes an illogical comparison between prices at the producer level and as time period ( a year ago), 所以改为 than those of a year ago.

但是！！曼哈顿论坛上Ron 大神在讲comparison时给的例子
gas prices were higher in 2007 than in 1997.

1/
right-hand element = "in 1997"

2/
this is legitimate (see write-up of previous example, which works in exactly the same way)

3/
"in 2007" is there; we're good.

--

gas prices were higher in 2007 than those in 1997.

1/
right-hand element = "[gas prices] in 1997"
(meaning of the pronoun is obvious, i hope)

2/
we want to compare prices, so the set-up is ok

3/
nothing works on the other side.  we need "gas prices in 2007" (in one piece), but only "gas prices" is there.
nope.

至此！！这句话的结构和og一样呀，为啥这里是两个年份相比呢？不用加those? 但是og上讲的是prices和年份相比了，求助各位大神！！到底哪个对呀？万分感谢！

附上链接Ron讲解链接

https://www.manhattanprep.com/gmat/forums/post108547.html?hilit=omission&sid=690f50b602b417b61a4cef36a0d8d0b6#p108547

zoeooxch

正好在重新复习comparsion，下面都是个人看法

虽然两句比较的都是prices，但是侧重点不同。


1. Prices at the producer level are only 1.3% higher now than a year ago

比较对象不同，prices 和 时间比较

2. gas prices were higher in 2007 than in 1997.

补充完整以后是 gas prices were higher in 2007 than （they were）  in 1997.
其实是侧重介宾结构的比较，省略了主谓