Human Introductions and Extinctions of Plant and Animal Species

Human introductions and extinctions of plant and animal species

A) have reduced to insignificance the floral and faunal differences between continents.
B) may result in unforeseen alterations to the original natural environment and to the economic potential of an area.
C) are,in relation to the immense natural diversity of plant and animal life,insignificant and easily matched by naturally occurring changes.
D) are the immediate cause of locally serious desertification and salinization problems.