that that 还是 what what
对于下面道题，是选哪个呢？that that 还是 what what?
His lecture was difficult and I didn’t know _________ he said meant in his lecture.
A. that B. what C. that that D. what what
许多同学一看选项首先就排除了C和D，认为这样两个“引导词”叠用的情况很少见。在A和B两个选项中，选项A肯定不行，因为它引导宾语从句时不能充当句子成分，所以便选择了B。其实此题的正确答案应是D，第一个what 用作动词 meant 的宾语，第二个what 用作动词 said 的宾语。
He was honest and told us all all he knew. 他很诚实，他把他知道的都告诉了我们大家。
句中的第一个 all 为 us 的同位语，意为“我们大家”或“我们所有的人”；第二个all 实为 all that 之省略，其中的 all 为动词 told 的直接宾语，被省略的关系代词 that 为定语从句中谓语动词 knew 的宾语。当然此句也可说成 He was honest and told us all what he knew.