Which sentence has the correct subject verb agreement?

a) heavy rains or fast-melting snow cause floods in many parts of the world.

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

Which sentence in this excerpt from leo tolstoy’s the death of ivan ilyich suggests that ivan ilyich and his wife couldn’t even agree on how to raise their children?

1. a poem that tells a story irony 2. taking on human characteristics narrative 3. a direct comparison between two things personification 4. words that are opposite the thoughts in a speaker's mind simile 5. implied comparison introduced with "as" and "like idiom 6. one's own manner of speaking metaphor

American history (is, are) studying the american colonies.