Portia for physics had once been very hard turned out to be a physicist.A. whomB. whoseC.

问题补充：

Portia，for physics had once been very hard，turned out to be a physicist.

A. whom

B. whose

C. that

D. which

答案：

A. whom

B. whose

C. that

D. which

解析：for whom(对她来说)引导一个非限定性定语从句，补充说明主语Portia。在介词后面只能用which或whom，不能用that。题干中如果没有for，则应该选whose。