Not once has she given in to any difficulty in her life and that's she is a strongwilled woman.
A. why
B. when
C. because
D. where
网友回答
A. why
B. when
(答案→)C. because
D. where
解析：考查表语从句。句意：她一生中从未向困难妥协过一次，这就是她是一个有着坚强意志力的女性的原因。is后跟从句作表语，why后跟原因，because后常跟结果。“she is a strongwilled woman”是“Not once has she given in to any difficulty in her life”带来的结果，故选C。