1) B
(I'm not so sure of this one) All of the other options have a steady impact on population regardless of the density of organisms except competition
2) D
Increased carbon dioxide levels would not hinder plant growth, and tsunamis aren't really linked to carbon dioxide levels. Increased carbon dioxide is unlikely to lower the air temperature so only D is left.
3) A
4) Three properties of water that allow it to sustain life are that it is adhesive, it is a good solvent, and cohesion. Adhesion is important in situations such as water travelling up xylem tubes in plants so that the water is not pulled down by gravity and can reach parts of the plant that need water. Cohesion allows the water being pulled up the xylem to stay together and for water molecules to be pulled when a neighbouring one is moved. Water being a good solvent allows inorganic minerals to be taken with water through vascular tissue, such as in the previous example.
There is a place in the lid where the fluid rushes to when you tip it, leaving the air bubbles in the cylinder of the bottle. In some companies it's a chemical inside the fluid that can evaporate over time and looses it's " magic" effect.
Lithosphere is the final layer on the planet Earth, erosion caused by wind (atmosphere) or rain (hydrosphere) may also wear down rocks in the lithosphere.
