In case I _____, I would try again.
If Joe’s wife won’t go to the party, _____________.
________ is known to us, May 12, 2008 was the day _______ Wenchuan earthquake happened.
They _________ have arrived at lunchtime but their flight was delayed.
China is one of the countries ________ the Mekong River flows.
He was _________by his colleagues though he himself didn’t think he had done anything special.