_____it’s late at night,______my father is still working.
We will have no water to drink ________ we don't protect the earth.
—You bought the car about ten years ago? —Yes.________ it's old,it still runs well.
Mark isn't coming to the concert ________________ he has got too much work to do.
-When will you go back to your hometown? - _______.
— Was it under the tree ________ you were away talking to a friend?— Sure. But when I got back there, the bike was gone.