She opened her eyes with a start and was about to cry out she heard her father urgently t

问题补充：

She opened her eyes with a start and was about to cry out she heard her father urgently telling her to keep quiet.

A. while

B. before

C. when

D. as

答案：

A. while

B. before

(答案→)C. when

D. as

解析：固定搭配be about to do sth when “刚要做某事这时”所以答案为C。