The best way may be is going over the notes on the chapter you were doing. Or going over the chapter once or twice.
Explanation:
Looking at the Ecological concept of Modern Ecology
we have
Atmosphere, Lithosphere, Biosphere, Niche, Environment, Habitat, Population, Ecosystem and Biotic community
Hydrosphere and Geosphere are not part
so Atmosphere is the correct answer
Yes, the region is probably experiencing climate change. This is due to impact of several practices that humans do to the environment. The melting of the polar ice caps and the direction of the wind passes through these states affecting or changing its weather. If humans keep doing this mother nature, humans will be left with a planet that's constantly changing and possibly inhabitable.
Even being a visual learner the trick is to take notes, even if you never look at the notes ever again its good to write them down, you are more likely to remember something you have written down rather than to just look at it. Science is something that could be easy, you just have to take it at your own pace, don't try to learn science by giving it a quick read or glance at it.