宾从句型
1、主句+whether（if）+从句
I don't konw whether/if he'll arrive in time.
2、主句（现在/将来）+从句（任一时态）
主句（过去）+从句（过去相应时态）
I konw you didn't konw what I think at all.
He asked me if I was reading the novel The Old Man and the Sea when he came in.
3、主句+从句(一般现在）从句表客观事实或真理
My mother told me that a friend in need is a friend indeed.
