Answer:
I am pretty positive its the last one, "How computer viruses can be prevented"
Explanation:
Computer Viruses are the problem, and how they can be prevented is the solution
Answer:
Rita will understand if you arrived late
Explanation:
The sentence's verbs that express a sequence of events is "Rita will understand if you arrived late".
This is because, the sequence of events is the way or structure of events as they come up in a story such as the beginning, middle and end of story has their own end and beginning.
The prepositional phrase for this sentence is "go until Friday." The word "go" is a preposition. Think of it as a squirrel and a log. To find a preposition, say "The squirrel (went) [insert preposition] the log." If it makes sense, it is a preposition. Then just find the phrase to go along with it!
