【单选题】Non-indigenous (non-native) species of plants and animals arrive by way of two general types of pathways. First, species having origins outside the United States may enter the country and become estab...
A.
Human factors affect species movement rates more than its long-term amount.
B.
Natural expansions of species account for their slow natural contractions.
C.
Natural environments created by human activities contribute much to species movement.
D.
Long-range movement of species depends on the geographic extent of human mobility.