.He is really an excellent doctor and he is to becoming an expert in this field. A. in a

问题补充：

.He is really an excellent doctor and he is to becoming an expert in this field.

A. in a way

B. by the way

C. on the way

D. under the way

答案：

A. in a way

B. by the way

(答案→)C. on the way

D. under the way

解析：短语辨析。in a way在某种程度上； by the way 顺便说说；on the way 在途中，正要成为；under the way在……方式下。句意：他是一个真正不错的医生，并且他正在成为这个领域的专家。故选C。