我对一下自己的答案，谢谢所有回答的人。
1.I find the book is very interesting.
I find the book ______ ____________.

2.I find it veryhard to learn English.
I find it _______ _________ to learn English.

3.He listened to the radio while he was doing his homework.
He listened to the radio _______ _______ his homework.

4.The little boy fell asleep while he was doing his homework.
The little boy fell asleep _________ ________ his homework.

5.The story is very interesting. And it is very instructive, too.
The story is _________ ________very interesting, ______ ________very instructive.

6.They seemed to know the answer.
________ _________ ________ they knew the answer the answer.

1.very interesting (作宾语补足语）
2.very hard
3.while doing (主语承前省略）
4.while doing
5.not only...but also (too的另外一种表达方式。不但...而且）
6.It seemed that (It作形式主语）

大家觉得不对的请指出来，谢谢。