— Mum, ______ are my shoes?— Under your bed. You should put away your things.

The students are _______ to know that elephants can walk quietly on tiptoe.

Michael Jordan is a man who never gives up in his life. And that's _________ he succeeds．

—How many people will come to Beijing next year?—It’s hard to say. ___________ people, I think.

We needn’t hurry all the way to the airport — the flight has been 　　　　 because of the bad weather.