John used to be such a computer buff that he spent a large part of his income ______ his computer whenever a new CPU was introduced.

【正确答案】 D

【答案解析】 动词词义辨析。根据句中a new CPU was introduced提供的信息，说明John upgrade(升级，提升)了计算机，其他选项均不符合逻辑。故答案为D。imbibe“吸收”。