the letter tears kept coming to her eyes.A. To readB. ReadingC. She was readingD. While

问题补充：

the letter, tears kept coming to her eyes.

A. To read

B. Reading

C. She was reading

D. While she was reading

答案：

A. To read

B. Reading

C. She was reading

(答案→)D. While she was reading

解析：考查状语从句。句意：当她读这封信时，眼泪不断地留出他的眼睛。不定式和分词作状语都和句子主语有一定得逻辑关系，句子只有一个主语。根据句子中的逗号，可知前文表示的是下文的时间条件关系，应用引导词，故选D，时间状语从句。