The mission of the U.S. Environmental Protection Agency is to protect human health and to safeguard the natural environment &#151; air, water, and land &#151; upon which life depends.
(The mission of the U.S. Environmental Protection Agency; is; to protect human health and to safeguard the natural environment &#151) (land &#151; depends; life)
The mission of the U.S. Environmental Protection Agency land &#151
is depends
to protect human health and to safeguard the natural environment &#151
life