Among and amongst normally mean the same thing. Use among for a straightforward modern choice. Use amongst when it suits the voice of the text, especially in a formal, literary, or British-English context.
Put an appositive next to the noun it renames. Use commas when the reader already knows which person or thing you mean. Leave out commas when the appositive is needed to identify that person or thing.
Say has diabetes and mentions malaria, with no article before the disease name. Say has a cold because cold is countable in this meaning. The flu is also a familiar expression, but flu without an article is common in some varieties of English.
Say Lake Geneva and Lake Victoria without the. Say the Alps and the Andes with the because they are mountain ranges. Say the Great Lakes because that name refers to a group of lakes and has an established article.
Assume usually means accept something as true without proof. Presume often means suppose something is true from available signs and can sound more formal. Only assume normally means take on a duty, role, or responsibility.
Assure someone that something is true. Ensure that something happens or is ready. Insure a person or thing against a financial risk through an insurance policy.
Benevolent is a formal adjective for a kind, helpful, or generous person or behavior. It can also describe something that suggests goodwill or an organization set up to do good.