短语词组短语by in twos and threes 三三两两地by twos in pairs 成双地by twos number 二by ones and twos 三三两两地;两两地;零零落落地;零零散散by twos and threes 三三两两地;零零星星;两三个一次;零星地by ones or twos 三三两两;零零落落by ones and by twos 三by y ones or twos 三三两两 返回 by twos