—Have you been to the United States?—Yes, only once. I ________ there only for seven days.
Some exercises appear to be ______ ones you have done, but on ______ second thoughts, you’ll find that they’re different.
—Thank you for having bought me a ticket for the World Expo in Shanghai! —________.
_______ what would happen, none of them could find a way out.
Students who pass the test will be ______to the next grade, as has been announced.
Now, the world’s focus is all on Shanghai ______ the 2010 world Expo is to be held.