It seems that you have missed the necessary details for us to answer this question, but hope this would help you. The line in the given passage that is considered a flashback is this: <span> She thought of her last day in middle school, seven years ago, when Sarah had given her an iPod. Have a great day!</span>
<span>Because the fire trucks arrived immediately, the house was saved.
the cause is the fire trucks arrived immediately</span>
You would never know what the setting is,if the characters are not known and if the settings are unknown the story would have to turn to the theme or the plot. when the charaters are unknown the effect is losing place in the story. It might be confusing but if it help letme know!!
The answer is smog hope i helped
THe second sentence is using present participle because you said " I promise" not "promised". Saying promise is when you are saying it at the time and saying promised means you've already said it. Like with how you said "kissed" instead of "kiss" in the first sentence.