that that 還是 what what

對于下面道題，是選哪個呢？that that 還是 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

許多同學(xué)一看選項首先就排除了C和D，認(rèn)為這樣兩個“引導(dǎo)詞”疊用的情況很少見。在A和B兩個選項中，選項A肯定不行，因?yàn)樗�引�?dǎo)賓語從句時不能充當(dāng)句子成分，所以便選擇了B。其實(shí)此題的正確答案應(yīng)是D，第一個what 用作動詞 meant 的賓語，第二個what 用作動詞 said 的賓語。

He was honest and told us all all he knew. 他很誠實(shí)，他把他知道的都告訴了我們大家。

句中的第一個 all 為 us 的同位語，意為“我們大家”或“我們所有的人”；第二個all 實(shí)為 all that 之省略，其中的 all 為動詞 told 的直接賓語，被省略的關(guān)系代詞 that 為定語從句中謂語動詞 knew 的賓語。當(dāng)然此句也可說成 He was honest and told us all what he knew.