Sentence Correction

It is said that Subordinating conjunctions such as "although" and "though" should be followed by a clause(subject+verb) but there are many instances in OG where such conjunctions have not been followed by a clause.
Eg-
Q48 from OG13: Though called a sea, the landlocked Caspian is actually the largest lake on Earth, covering more than four times the surface area of its closest rival in size, North America's Lake Superior.(choice c and it is the correct answer).

OG13 - Q36: Along with the drop in producer prices announced
yesterday, the strong retail sales figures released
today seem like it is indicative that the economy,
although growing slowly, is not nearing a recession.
(although portion is not underlined)

Please let me know how to go about it.

But here the explanation says that although needs a clause

OG 13 Q 17:
Sunspots, vortices of gas associated with strong
electromagnetic activity, are visible as dark soots on
the surface of the Sun but have never been sighted on
the Sun's poles or equator.
(A) are visible as dark spots on the surface of the
Sun but have never been sighted on
(B) are visible as dark spots that never have been
sighted on the surface of the Sun
(C) appear on the surface of the Sun as dark spots
although never sighted at
(D) appear as dark spots on the surface of the Sun,
although never having been sighted at
(E) appear as dark spots on the Sun's surface,
which have never been sighted on

here the official guide explanation for although(option c &d) says:

C. Although typically introduces a subordinate
clause, which has a subjectand a verb,but
here there is no subject and sighted'is not a
complete verb.
D. Although usuallyintroduces a subordinate
clause,but there is no subject of the clause
and having been sighted is not a complete verb
phrase.

Thanks!!!
So you mean if Although/though/other_coordinators come at the beginning they can be followed by a phrase or a clause but if they come at the end they ALWAYS need a clause ? Is it a rule ?
And what if they come in the middle ?

pramitmishra0607 wrote:But here the explanation says that although needs a clause

OG 13 Q 17:
Sunspots, vortices of gas associated with strong
electromagnetic activity, are visible as dark soots on
the surface of the Sun but have never been sighted on
the Sun's poles or equator.
(A) are visible as dark spots on the surface of the
Sun but have never been sighted on
(B) are visible as dark spots that never have been
sighted on the surface of the Sun
(C) appear on the surface of the Sun as dark spots
although never sighted at
(D) appear as dark spots on the surface of the Sun,
although never having been sighted at
(E) appear as dark spots on the Sun's surface,
which have never been sighted on

here the official guide explanation for although(option c &d) says:

C. Although typically introduces a subordinate
clause, which has a subjectand a verb,but
here there is no subject and sighted'is not a
complete verb.
D. Although usuallyintroduces a subordinate
clause,but there is no subject of the clause
and having been sighted is not a complete verb
phrase.

A VERBLESS CLAUSE is a clause in which the subject and verb are omitted, but their presence is understood.
The omitted verb is usually a form of TO BE.

A verbless although clause must be NEXT TO THE OMITTED SUBJECT.
From the OG for Verbal:
Although eradicated in the United states, POLIO continues elsewhere.
Here, the verbless although clause is correctly placed next to the omitted subject (polio).
Implied meaning:
Although [it has been] eradicated in the United states, Polio continues elsewhere.
The words in brackets are omitted, but their presence is understood.

The following structure would be incorrect:
Polio continues elsewhere, although eradicated in the United States.
Here, the verbless although clause is NOT next to the omitted subject (polio).

In C, although never sighted (a verbless although clause) is NOT next to sunspots (the omitted subject).
D presents the same issue.
Eliminate C and D.

Thanks!!
Is it always true for all coordinating conjunctions ?

I mean can we say that "all coordinating conjunction verbless clauses must be next to the omitted subject otherwise they need a subject and a verb" as a rule ?

pramitmishra0607 wrote:Thanks!!
Is it always true for all coordinating conjunctions ?

I mean can we say that "all coordinating conjunction verbless clauses must be next to the omitted subject otherwise they need a subject and a verb" as a rule ?

Better:
A verbless clause should be AS CLOSE AS POSSIBLE to the implied subject.