【答案】He isn’t such a man____he used to be.

题目：
He isn't such a man____he used to be. 只能用that而非which：先行词还原时为定语从句的表语，如He isn't the man that he used to be. such…as…与such…that…的区别在于：as表示”像“，不是同一物。而that表示同一物。