1、首先要弄清和记住： Do you think后面的从句语序永远都是陈述句语序.
2、因为其实任何一个疑问句只在一个地方表现出疑问,那就是主句上,其它的从句保持陈述语序.
例如：
Is he a good student?
Do you think (that) he is a good student?
Why do you think (that) he is a good student?
当然还有其它也是同样.
Do you know (that) she is my sister? 从句陈述语序.
How do you know she is my sister?
Who told you she is my sister?
我们把这种规律叫做语法.其实很容易记,也很合理.要是记不住就记个最短的句子吧!