● 题目：

　　In one experiment, subjects aged 6 to 22 were shown drawings of female faces that had different sized pupils, and asked to choose the one which was "happier".

　　● 分析：

　　全句主语是subjects，有两个并列谓语were shown和and asked，都是被动语态，that had different sized pupils是定语从句做drawings of female faces的定语，which was “happier”是定语从句做the one的定语，过去分词短语aged 6 to 22是subjects的后置定语。