Which of these is not a point source pollution 1. nitrates found in a river
2. someone dumping used oil in their backyard
3. factory smokestack
4. leaking oil tanker

The rocks expand when there hot/warm  and contract when they are cold.

There is no graph to look at on here, but i shall explain them to you. a line graph is just in its title it’s a graph with a line running through the dots to show an increase or decrease. a bar graph is used to show how much or how little something is so a comparison. a scatter plot is used to graph points to tell the data. and i don’t know what a histogram is.