He said something and I understood it.He said something ____？

选择：that
解析：当表示事物的先行词是或者含有下列三种情况,关系代词只能用 that——
1、不定代词,如：
* He said (something) that I understood.
* That is the (only thing) that I have never see before.
2、序数词,如：
* This is the (first) that he sends to me.
* It is the (second day) that I am looking forward to.
3、形容词最高级,如：
* It is (the most resonable way) that can meet your need.
* (The best solution) that answers for the problem has been worked out,7,但《新概念英语》第二册第125页的第7题，答案是：which 。如何理解？答案有误吗？题目欠佳吗？谢谢！,选B，which指代something,2,选A，something，anything，等做先行词，定语从句用that 引导,2,To be or not to be 是什么意思？,2,选A，something，anything，等做先行词，定语从句用that 引导,1,答案绝对是B,呵呵,0,选A，不定代词做先行词，定语从句用that引导。,0,He said something and I understood it.He said something ________ I understood.
A.that B.which