verb omission in parallelism [edited - banned source]

[kgc]

I saw this sentence in OG 11,

[deleted - OG is banned source]

I do not understand why the correct answer should be
than those of any other

Shouldn't a verb be inserted to ensure the parallelism like this:
than are those of any other?

Many thanks!

[JonathanSchneider]

I had to delete the problem itself, because we cannot post from the OG here.

However, in general:

when you are just comparing between two nouns, you do not need the "are." You would want to include the "are" in two circumstances:
- when there has been a lot of other junk in the middle, so that you need to remind yourself what you're connecting back to
- when there are multiple nouns that might sound like they are the one we're connecting to (in other words, also for clarity)

but when the structure is simpler, the "are" is unnecessary.