I'll just give you a start.
The thing that impacted the whole world was social media. This is Facebook, Twitter and Instergram and so much more.
Explain them
Good points (global communication)
Bad points ( bullying)
Setting: Greg’s house (which is on Upper Surrey street)
Time: middle school
The noun in this sentence which is uncountable, meaning that it names something that cannot be counted is the noun water.
You cannot count how many waters there are - it is uncountable. The other nouns, students and pitcher are countable, so they cannot be the correct answers, but rather water is.