I can’t find my book, and I don’t know _____ —Is it in your bag

You ________ pay too much attention to your reading skill, as it is so important.[ ]

Which of the following word matches the sound /b/

Shirley, could you please tell me __________- No problem. He told me about it just now.

Whose notebook is this— It ________ belong to Lucy. Look, hername is in it.