GRE Text Completion: JiJing 1373-GRE填空机经1373题 - 5FSH7PI72K754D08A

Geologists suggest that as the most productive oil reservoirs begin to dry up, the expensive cost and high risk of drilling in the marginal area becomes less ____________ and more acceptable. A. onerous B. efficacious C. auspicious D. benign E. natural