The prepositional phrase is "on a high shelf" since ON is a preposition.
The correct answer would be C<span />
My grand mom will visit us again next year.
Since it will snow for the rest of the day, Alvi will read a book by the fireplace instead.
The boat will turn around once it gets close to the waterfalls.
When Jean returns, she’ll show you the directions to the station.
My Nephew Jarraf will arrive from Bangladesh tomorrow. I am very excited since he’ll be staying with us for the entire holidays.
I hope this is correct :)
It is important because the sources tell you whether the article was credible. When you have an article that has bad source, you are running the risk of having, wrong, opinionated data. This can discredit you paper if you use it.