Principal White has been working in the school for about 20 years, all his energy to teaching and researching as well as the running of a healthy school．
A. devoted
B. devoting
C. to devote
D. and devote
网友回答
A. devoted
(答案→)B. devoting
C. to devote
D. and devote
解析：后半句是一个伴随状语，现在分词作伴随状语表示主动关系，过去分词则表示被动关系，这里Principal White与devote 是主动关系。