The students in the class were four groups before they started the game.A divided into B s

The students in the class were four groups before they started the game.
A divided into B separated into C divided from D separated into

解析：短语辨析. separate一般指是从……分离、挑拣出来的意思，常用的词组有separate from，也就是从一个大的整体里分出来；divide一般是把……分成几部分的意思，常用的词组有divide sth into,一般是要通过切、割、劈等手段的，是把一个大的整体分成几个小的部分。句意：在他们开始做游戏之前，这个班的学生被分成四个组。结合语境可知选A。

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