应该去掉that/ that 与特殊疑问词引导宾语从句不能重叠使用.
which major 是从句的主语
又如：I don't know that he has come back
I don't know what he was doing .I spend much time thinking about what major is suitable for us 这句话写对了吗 如果错了怎么改？对了thinking about后面可以接从句？可以的。又如Please think about what i said just now.think后接that 宾语从句时，没介词。如 I think that he is right.