问题补充：
单选题____,IhaveneverseenanyonewhoisasenergeticasBarackObama.A.As long as I have interviewed many leadersB.Since I have interviewed many leadersC.Many leaders although I have interviewedD.Many leaders as I have interviewed
答案：
D解析考查特殊句式。句意为：虽然我采访过很多领导人，但是我从未见过像奥巴马这样精力充沛的人。此处是as引导的让步状语从句，句中的as可用though代替，不可用although，因此C项错误。A项表示“只要我采访了很多领导人”；B项表示“既然我采访了很多领导人”，语句都不通顺。
