—I’m sorry for being so late. I should have called you earlier.--_________. I’ve just arrived.
Although the causes of cancer _____, we do not yet have any practical way to prevent it.
At this time tomorrow ____over the Atlantic.
Susan decided not to work on the program at home because she didn’t want her parents to know what she_____.
----Did you tell Julia about the result? -----Oh, no, I forget. I _____her now.
After the long journey, the three of them went back home, ______.