问题详情：
Mike ________ his computer and checked his e-mail.
A. turned on B. turned off C. turned up D. turned down
【回答】
A
词汇辨析题。看*四个词组的词义，A. turned on 打开，B. turned off 关掉，turned up加大音量，D. turned down 缩小音量。句义应为“Mike打开电脑，检查他的e-mail.” 故选A。
知识点：动词和动词短语
题型：选择题
