单选题 I was ______ in my reading, and didn't at first hear the doorbell ring.

【正确答案】 B

【答案解析】[解析] 各项的意思为：immured监禁，禁闭；immersed沉浸，使陷入，be immersed in专心于，沉浸于。busy忙碌；be busy doing忙于做某事；infatuated昏头昏脑的，使入迷。答案是B。