E obscures the meaning: it suggests that one might not expect stationary crests and troughs to be formed by rapidly moving air. Nowhere is the original is it suggested that the crests and troughs are what one might not expect to be formed.

lunarpower wrote:

Kajiabeat wrote:the explanation OG gives about E is "Th e subordinate clause in the passive voice following although is awkward and unclear." I cannot understand it well.how this clause become askward and unclear?

well, "awkwardness" is not something that can be studied or quantified formally, so it's not worth going down that road. (in general, the only people who can recognize "awkwardness" are native speakers of a language -- and even then, only a small fraction of native speakers are even decently good at doing so.)

the best way to eliminate (e) is to notice that it is much, much less parallel than (c).
compare:
crests and troughs that remain stationary although the air that forms them is moving rapidly
stationary crests and troughs although they are formed by rapidly moving air

the first of these is much more parallel, so you can eliminate the second.

--

by the way, it's "troughs", not "toughs".

lunarpower wrote:

kevincanspain wrote:A is perfectly clear: it conveys the fact that the crests and troughs remain stationary (motionless) even though the the air that forms them (i.e. the crests and throughs) is moving rapidly. C corrects the verb error.

E obscures the meaning: it suggests that one might not expect stationary crests and troughs to be formed by rapidly moving air. Nowhere is the original is it suggested that the crests and troughs are what one might not expect to be formed.

The following two sentences differ in meaning in much the same way:

It is suprising that the woman chosen to be the next head of the IMF is a European lawyer.
It is surprising that the next head of the IMF will be a female European lawyer.

that's a nice explanation.

i was trying to give the easiest thing to find; this explanation is, of course, much more complete than mine. however, either method may be used to arrive at the correct answer.

lunarpower wrote:

sophiesaurabh wrote:Option (C) tends to covey that the air that forms crests and troughs is moving rapidly "right now" because of the use of present continuous tense. Isn't that not the intended meaning? should it not be "moves rapidly"?

I know since it is an OG OA, it must be correct, but what is the fault with my logic?

Please explain.

the "right now" sense of this tense applies when it is used in the main clause of a sentence.

however, when it is used in a subordinate clause, then its meaning isn't necessarily "right now" anymore -- the meaning is "going on at the same time as the action in the main clause, and viewed as a background / ambient event".
e.g.,
James is always calm, even when everyone else is going crazy.
--> this doesn't necessarily mean that everyone else is going crazy right now; rather, it just means that james still, in general, remains calm when things *do* happen to be that way.
same here.