【单选题】

Surprisingly to those who view the ocean floor as a uniformly ______ waste, each vent in the floor, where seawater is heated by the earth’s inte-rior magma, has been found to be an island-like ______ with its own distinctive faun

A、
A、teeming...habitat
B、lifeless...enclave
C、barren...oasis
D、sunken...grotto
E、hazardous...environment