“Where is Tom?”

“He hasn't come to school today. I think he ______ be ill.”

--Jack's never worked hard at English, _______?

-- _______ , so he can't answer the question in English, I think.

---Where is John?

---He hasn't come to school today．I think he ________ be ill．

---I think our chemistry teacher is working hard．He teaches us ______．

---Yes, but he hasn't come today．He doesn't feel ______．