Which sentence has the correct subject-verb agreement?
heavy rains or fast-melting snow causes floods in many parts of the world.
heavy rains or fast-melting snow cause floods in many parts of the world.

A). Heavy rains or fast-melting snow causes floods in many parts of the world.

Explanation:

Subject-verb agreement is demonstrated as the grammatical rule which implies the agreement of subject and verb in terms of number. It implies that a singular noun must correspond to a singular verb while a plural must correspond to a plural verb.

As per the question, option A implies a correct subject-verb agreement as it includes the subjects 'Heavy rains' and 'fast-melting snow' are linked by coordinating conjunction 'or' that turns it singular and therefore, the verb must also be 'singular'(causes). Thus, option A is the correct answer as in option B the subject and verb do not agree in number.

faulty parallelism is a grammar construction where there is no balance in the parts of a sentence they have a similar meaning but the grammar structure is not equivalent.

the correct version of this faulty parallelism in the sentence is:

jefferson wrote the declaration of independence, and he was the nation's third president.

the problem with the first version is that the sentence:

"jefferson was both the writer of the declaration of independence"

presents jefferson as both a subject and an agent for the verb "write" because if he was "the writer" then the declaration of independence was written by him, besides that fact, the sentence presents a dependent clause.

while the second sentence:

he was the nation's third president.

presents a basic subject+verb+object structure

so, to give a proper balance to the structure, or better said, to give a parallel structure, we must write a basic s+v+o structure in both sentences:

jefferson wrote the declaration of independence, and he was the nation third president.

atmospheres is the answer to your question.

explanation: