题干
Everyone was silent as the judge ____ (宣布) the winner of the competition.
答案(点此获取答案解析）
announced
Everyone was silent as the judge ____ (宣布) the winner of the competition.
=1（0＜a＜b＝的半焦距为c，直线l过（a，0），（0，b）两点.已知原点到直线l的距离为
c，则双曲线的离心率为（ ）