He devoted himself to his research and got many achievements.
A. certainly
B. extremely
C. carefully
D. entirely
网友回答
A. certainly
B. extremely
C. carefully
(答案→)D. entirely
解析：考查副词：A. certainly当然，B. extremely非常，C. carefully仔细地，D. entirely 完全地，句意：他完全致力于研究得到很多的成就。选D。