It was not she took off her dark glasses I realized she was a famous film star.A. when;

问题补充：

It was not she took off her dark glasses I realized she was a famous film star.

A. when; that

B. until; that

C. until; when

D. when; then

答案：

A. when; that

(答案→)B. until; that

C. until; when

D. when; then

解析：“直到她摘下太阳镜，我才认出她是一位著名的影星。” 题干是I did not realize she was a famous film star until she took off her dark glasses 的强调句式。在转换成强调句时，要将主句中的否定词not前移到until 之前。这个句子看起来是一个否定句，但表示的是肯定意义。