C2 giving all your attention to something全神贯注的;专心致志的
She was so engrossed by/in the book that she forgot the cookies in the oven.她看书看得太入迷了,以至于忘了烤箱中正烤着饼干。
They were so engrossed in/with what they were doing that they didn't hear me come in.他们专心致志地做着手头的事,连我进去都没有听见。