1 . — I’ll ask the teacher about the attributive clause. I’m very puzzled about it.
— That’s just __________ most of our classmates have doubt.

2 . The reason for their failure you know is ________________ they are lazy. （用适当的词填空）

4 . I’m going to choose English as my major because English is ____________ my interest lies. (用适当的词填空)

5 . What surprised us was ________ he worked out the problem in such a short time. (用适当的词填空)

6 . The system works well in the lab, but the question is ______________it will work in reality. (用适当的词填空)

8 . Being reflective is an important part of active learning. That is ________ you are thinking actively and critically while reflecting on the learning materials. (用适当的词填空)

9 . He is no longer __________ he used to be. (用适当的词填空)

10 . The reason why I can’t go travelling with you is________________ I have something unexpected to deal with. (用适当的词填空)