@ mohit

we don't need "are" because there is no ambiguity. if the sentence were ambiguous without "are", then we would need to insert it. (note that the sentence is not actually incorrect if you add "are"; you just don't have to.)

examples:
i know more about biology than chemistry
correct. (i could say "...than about chemistry", but i don't have to, since there is no ambiguity here)

i know more about shakespeare than my brother.
here, i NEED a helping word.
if i mean that i am superior to my brother in terms of shakespeare knowledge, then i have to add "does".
if i mean that i know more about shakespeare than i know about my own brother, then i have to add "about".

same deal here. there's no ambiguity (as in the first example here), so you don't need a helping word.

Hi Ron !!!

This is just too ambiguous !

How to decide in the Exam time that are is creating redundancy or adding to clarity ? :-)

Thanks
Mohit

I suppose the concept is as below

i know more about biology than chemistry

Two options
Option#1
i know more about biology than i know about chemistry = chemistry acting as object = correct

Option#2
i know more about biology than chemistry know about biology. = wrong. Chemistry cannot act as subject

Since no ambiguity so correct to use as "i know more about biology than chemistry"

But in case 2.....
"i know more about shakespeare than my brother."

Both object and subject are possible:

Option#1
=======
i know more about shakespeare than my brother i know more about shakespeare than my brother. = brother acting as subject...sentence makes sense.

Option#2
========
i know more about shakespeare than i know about my brother. = brother acting as object...sentence makes sense.

Since both the above make sense...so we need helping verb......

Probably here we need to understand what does the 2nd word of comparison mean....as above....

Please correct me if I am wrong here.

two reasons.

(1) it's not necessary.
in general, you only put helping verbs (like this one) into the second half of a parallel construction for one of two reasons:
- the sentence is AMBIGUOUS WITHOUT the helping verb (click here for further thoughts on this)
or
- the parts of the parallel construction are so obnoxiously long that the sentence is difficult to understand without the helping verb.

(2) that's not the usual convention for the form "as ADJ as ...".
for instance, if i'm as old as my twin brother, then that's how i say it. i'm not "as old as is my twin brother".

Thanks Ron !!!

Do you mean "environment and natural resource base" is actually singular?
I thought it should be plural b/c there are actually two things: environment + natural resource base, both of them are non countable words though.

Please explain.
Thanks!

and if "environment and natural resource base" is plural. would Choice B be correct too?

Why "are" is not necessary in A?

the best way to process "as varied as" here is as an IDIOMATIC EXPRESSION.

here's a valid way to think about it: you can substitute "including" for "as varied as"; the sentence should still work.
these two don't have exactly the same meaning - i.e., "including" isn't the SAME as "as varied as" - but, if one of them is grammatically ok, then so is the other.

--

the countries themselves aren't "varied" (i.e., it would be incorrect to say that "the countries are varied"), so it's not correct to use the verb "are".

Hi Ron,

Replacing "as varied as" with "including" to look for the correct answer is very helpful. Are there any other comparison idioms that can be replaced with "including" to help find the right grammatical construction?

Thanks!

hmm
i can't think of any others off the top of my head that are this exactly replaceable, but "limited to" is also pretty close.

Ron, why we can't say"the contries are varied"? Sorry I can't get it....

I believe Ron's point is that countries as varied as China, the Netherlands, and Hungary does not imply that any one of these countries is varied, whatever exactly that would mean, but that they vary from one another.

Ron, pls help

In a posting in this thread, it is said that we need verb when there is ambiguity. D is clear and dose not need verb. why D is wrong.(the following is discussed in thid forum already). DOSE THIS MEAN WE PREFER PARALLELISM EVEN THERE IS NO AMBIGUITY.

A study published in the British Medical Journal showed that woman who ate nuts more than five times a week were about one third less likely to suffer from coronary heart diseases as those who ate no nuts at all.

A. as those who ate

B. as women who ate

C. as those eating

D. than women eating

E. than were those who ate

Ron, pls, help

after studying the two above problems, can I conclude that

BECAUSE THE LEFT SIDE CONTAINS A VERB, THE RIGHT SIDE MUST CONTAIN A VERB. IF THE LEFT SIDE DOSE NOT CONTAIN A VERB, THE RIGHT SIDE DOSE NOT NEED A VERB.

thanghnvn, you are seriously over-complicating the issue.

look at the structures:
(d): women who ate... vs. women eating...
(e): women who ate... vs. those who ate...

(e) is clearly better. (d) is inferior to (e), because the two structures are written in completely different ways, while they are written identically in (e).