--- Do you ________ what Janet said about the aliens?

--- I'm afraid not, though I ________ her.

---Now that you like the portable personal computer so much, why not buy one? It is of great use to your work．

---Well, I can’t afford _________ computer at present．

---May I go and play with Tom this afternoon, Mum?

---No. You can't go out ________ your homework is being done.

---Do you think we can get there on time?

---Yes, ________ the car doesn't break down.

--You know the exact date ________ you posted the letter, don’t you?  

--No. But I remember it was a holiday, _______ happened to be Mother’s birthday.  

---Have you ever visited the 2010 Shanghai World Expo?

---Yes．When I was in China, I ________ it twice．

---_________ you make so much noise?

---Sorry．I’ll take care not to．