He's engaged in writing a Novel.

他致力写一本小说。

youdao

He's engaged in writing a novel.

他致力写一本小说。他致力写一本小说。

youdao

He was engaged in writing letters.

他在忙着写信。

youdao

Last time I talked just briefly about Yeats's interest in automatic writing, a practice that he engaged in with his wife.

上次我简要提到叶芝对,自动书写的兴趣，他和妻子所实践的。

耶鲁公开课 - 现代诗歌课程节选

"Information has been received that he is a close friend of Picasso and is engaged in writing his biography".

BBC: Today - The Lee Miller file

Mercury General Corp. is engaged primarily in writing all risk classifications of automobile insurance in a number of states, principally California.

FORBES: Fairholme Fund Buys Mercury General, Sears, Jefferies and Wells Fargo Warrants; Sells Citigroup and Goodman Sachs

While the latter four have not been named at this writing, it seems as though the Obama Justice Department is not saying they actually were engaged in espionage.

CENTERFORSECURITYPOLICY: From Russia, with love