preoccupied

他太专注于自己的项目，甚至没听到电话铃声。

He was so ___preoccupied with his project that he didn't even hear the phone ring.

他太专注于自己的问题，甚至没注意到我在跟他说话。

He was so ___preoccupied with his own problems that he didn't even notice me talking to him.