in doing 开头的句型

如:

In handing down this sentence， Judge said it‘s nessesary to deter others

这里的In doing 相当于When handing down this sentence

表示“在做...时”，可看做一个时间状语

doing开头一般来说 是动名词做主语，位于句首，谓语动词要用单数。

Playing on the beach is a pleasant thing for me.

Doing exercise every day makes us healthier and healthier.

1，be fortunate in doing sth做某事是幸运的 .

2，be busy in doing sth忙于做某事 .