cān / jiā / shuāng / máng / shì / yàn / de / huàn / zhě / hé / yī / shēng / dōu / bù / zhī / dào / fēn / zǔ / qíng / kuàng

参加双盲试验的患者和医生都不知道分组情况。

Neither the patients nor the doctors in the double-blind trial knew the group assignments.