> If you are asked about the composition of atmosphere, look for the Troposphere.

> If you are asked about the composition of the lithosphere, remember that the lithosphere is the crust.

Read questions carefully! You may be asked about the composition of the crust as a % of mass or a % of volume. Choose the right column! 

> If you are asked about the composition of water (the oceans, a river, any water) remember that the hydrosphere is water.