__________ is a mixture of minerals, organic matter, liquids, and gases that can provide a medium for plant growth.
A)
Sand
B)
Clay
C)
Soil
D)
Silt
E)
Humus
Which species have a short life span and reproduce in large numbers over a short period of time?
A)
threatened species
B)
invasive species
C)
k-selected species
D)
nonnative species
E)
r-selected species
