The magic act was just a curtain-raiser for the circus performers.这段魔术只是马戏表演的序幕。The President's address tonight from the Oval Office is a curtain-raiser for the economic policy message set for delivery to Congress on Wednesday.美国总统今晚于总统办公室发表的讲话是将于周三提交国会的经济政策的前奏。