---Is there ______ you don't understand?

---I think ______ is quite clear.Thank you.

一Hello．Is Mr．Fred  available  now?

一       ．

—If you like the model car, you can _____ it. I don’t want it.

—Thank you very much.

一We only have seats in the very back row．

一       ．I’ll take two tickets．

---Bill, can I get you anything to drink?

---______.

—It is very cold today.

—Yes.Surprisingly cold __________ May.

—Sorry, but we have no more than one ticket for 3-D Titanic now．

—That's OK．I'll take _____．

—Would you have come to his help, had you been free?

—Yes. But I______ engaged.

---Which book do you want, the chemistry book or the English book?

--- ________ .