For Most of Human History, We Have Received Many Ecosystem

Multiple Choice

For most of human history, we have received many ecosystem services free and have taken them for granted.These include clean air, clean water, pollination, and flood control by wetlands.Compared with a century ago, these types of ecosystem services seem to be

A) unchanged.
B) degraded in quality.
C) improved in quality.
D) more available.
E) not measurable.