Listen! There is a knock on the door．Who _____ it be?—It must be Jack．Just now I sent for him．

People that lived in the mountains didn’t have wells in the past, so they had to ______ water from a stream far away.

1My father is in Beijing fora long time. I’m really looking forward ___ him．

Thanks for the lift I do appreciate it— _____

I don’t know ______or not Simon will come here.—Don’t worry. ______he comes, I’ll call you.