There were a lot of people in the park. We had ______ to take a rest, so we got very tired.
—Have you ever written a letter to your friend? —Yes, I.
—Have you received the books which ______ online? —Not yet.
This summer holiday I did an English course which ____ for four weeks.
Tom is going to watch a famous singerher latest CD on weekends.
Four years, from the 2004 Olympics to the 2008 Olympics, _____ a long time to wait for Lin Dan.