Gerald Middleton was a man of mildly but persistently depressive temperament. ________ men are not at their best at breakfast.
句意：杰拉尔德·米尔顿是一个温和但会持续抑郁的人。这样的人在早餐时状态并不好。such 回指了前句中的限定词“of mildly but persistently depressive temperament”，具有前后照应的效果，使得这个语篇衔接得非常好。故选D。