Neither of these are minerals, B.
Its not A because, they are not natural materials but instead made up of natural materials, like a rubber tree.
Its not C because, like I said, plastic is made from rubber trees, this garentees it doesnt have a crystal structure.
Its not D because, concrete is not a mineral and has indefinite composition.
Heartwood. In contrast to sapwood, a term for the dead, clogged xylem cells near the center of a tree. Heartwood is the tree's main column of support.
<span>D. Lancelet, are examples of an invertebrate chordate:)</span>
Autobiographical memory refers to memory of specific events that had occurred during the course of one' lifetime. Autobiographical memory is divided into two major groups which are episodic and semantic memories. Episodic memory recollects time, location and people while semantic memory recollect general facts. An example of autobiographical memory is the memory of college graduation event.
D.Use a computer simulation model of the potential forest populations.
