Question

While watching television, __________.

                A．the doorbell rang                           B．the doorbell rings

            C．we heard the doorbell ring          D．we heard the doorbell rings

Answer 1

C

解析:

        非谓语动词作状语的用法。根据前半句的While watching television推断主语必须是“观看电视”这动作的发出者，即we；同时主句有have sb. do sth.的句型，省略了to的不不定式做宾补。