Question

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

A．whom

B．whose

C．that

D．which

Answer 1

for whom(對她來說)引導一個非限定性定語從句，補充說明主語Portia。在介詞后面只能用which或whom，不能用that。題干中如果沒有for，則應該選whose。