SC -GMAT paper tests

doing so refers back to some action already mentioned.

You could substitute what doing so refers to for doing so.

The Romans continued to use lead vessels in making wine even after they had been warned that they might be poisoning themselves by doing so.

The Romans continued to use lead vessels in making wine even after they had been warned that they might be poisoning themselves by using lead vessels in making wine.

Mo2men wrote:However, I can't understand difference usage of 'doing so' in Choice C & D.

REFLEXIVE PRONOUNS are himself, herself, itself, themselves.
A reflexive pronoun may serve as an OBJECT only if the subject and the object are THE SAME.
JOHN threw a party for HIMSELF.
Here, John (subject) and himself -- a reflexive pronoun serving as the object of the preposition for -- refer to the same person.
Thus, the usage of a reflexive pronoun is correct.

C: Doing so might be poisonous for themselves.
Here, doing so is the subject, while themselves -- object of the preposition for -- serves to refer to the Romans.
Since the subject and the object are NOT the same, the usage of a reflexive pronoun is incorrect.
Eliminate C.

D: They might be poisoning themselves by doing so.
Here, they (subject) and themselves -- the direct object of poisoning -- both serve to refer to the Romans.
Since the subject and the object are THE SAME, the usage of a reflexive pronoun is correct.

GMATGuruNY wrote:

Mo2men wrote:However, I can't understand difference usage of 'doing so' in Choice C & D.

REFLEXIVE PRONOUNS are himself, herself, itself, themselves.
A reflexive pronoun may serve as an OBJECT only if the subject and the object are THE SAME.
JOHN threw a party for HIMSELF.
Here, John (subject) and himself -- a reflexive pronoun serving as the object of the preposition for -- refer to the same person.
Thus, the usage of a reflexive pronoun is correct.

C: Doing so might be poisonous for themselves.
Here, doing so is the subject, while themselves -- object of the preposition for -- serves to refer to the Romans.
Since the subject and the object are NOT the same, the usage of a reflexive pronoun is incorrect.
Eliminate C.

D: They might be poisoning themselves by doing so.
Here, they (subject) and themselves -- the direct object of poisoning -- both serve to refer to the Romans.
Since the subject and the object are THE SAME, the usage of a reflexive pronoun is correct.

Doing so might be poisonous for them
Is this version correct?
Thanks

aflaam wrote: Doing so might be poisonous for them
Is this version correct?
Thanks

This revision does not convey a logical meaning.
An action such as doing so cannot be poisonous.
Here, the LEAD IN THE VESSELS is poisonous, not the act of wine-making.