While watching television, ________.
A. the door bell rang B. the door bell rings
C. we heard the door bell ring D. we heard the door bell rings
While watching television, ________.
A. the door bell rang B. the door bell rings
C. we heard the door bell ring D. we heard the door bell rings
C
：watching的逻辑主语一定是句子的主语，能作其逻辑主语的只有C项和D项中的we；又因hear之后作宾补的应是省略to的不定式，故选C。