题目

下列细胞器或结构中不会发生碱基互补配对的是 A．线粒体、中心体                       B．叶绿体、染色体 C．高尔基体、内质网                   D．核糖体、中心体 答案：C— Why weren't you at the meeting?　　— I ________ for a long distance call from my sister in America.A．was waitedB．was waitingC．has waitedD．have been waiting