A. Mass extinction is the answer
Xylem carries water and dissolved nutrients
The Neolithic marks the period when our specie developed farming and domesticated animals.
A group of people are building a house. They have a large package of building materials that needs to be moved. A block and tackle, a type of pulley, is used to pull the material up so it can be set in the back of a truck.
Nice shift is the change in behavioral or feeding patterns by two or more competing populations to reduce interspecific competition. Interspecific competition is a type of competition between organisms of different species. A niche is a full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions.
