To study this concept one study had participants play one of two combat games.

为了研究这个概念，一项研究中要求参与者们分别玩一款格斗游戏。

An online statement thought to be written by the El Paso gunman mentioned the combat game " Call of Duty" .

在一份被认为是埃尔帕索枪手的在线声明中有提到战斗游戏" 使命召唤" 。