现场投屏操作
一、通过鼠标点击大屏功能区进行操作「抽奖需要用空格键抽取幸运用户」
二、通过快捷键对大屏进行操作「通过快捷键的好处，用户不会感受鼠标在不断移动，连贯性好」。具体快捷键如下图1所示：
图1
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