--- 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.