问题
选择题
The idea for the new machine came to Mr. Baker ______ to his invention recently.
A．while devoting
B．while devoted
C．while he was devoted
D．while devoting himself.
答案
答案：C
while后主语及助动词不能省略，因为两句主语不一致
Mr Baker thought of the idea for the new machine (B / D) to his invention recently.