How does phone use before bedtime affect sleep What is the independent variable & dependent variable?

How well do different plant species tolerate salt water?

What is the independent variable & dependent variable

phone use before bed time can effect your sleep schedule and not only that, it will effect the way you think in a slower way because you used it too much before bed. It will drain your mind of energy and it is unhealthy to use electronics for more than 45 minutes.

Explanation:

and your question what topic are you in trouble with?

different routes can lead to sammy to different places, with different roads.   if you check a map, you can see the routes.   try to make connections of the places and count how many there are.   hope this : )