Unfortunately, the research was limited increasing economic profits, protecting the environment.
A. to; other than
B. by; rather than
C. to; rather than
D. by; more than
网友回答
A. to; other than
B. by; rather than
(答案→)C. to; rather than
D. by; more than
解析：原句意思，不幸的是，这份研究局限于提高经济利益，而非环保。be limited to 局限于 other than 不同于rather than 而不是 more than 多于，故选C。