You can only be sure of __________ you have at present; you cannot be sure of something __________ you might get in the future.
I’d like to go straight to help people, ________ when they are in trouble.
My plane _________ at 8:30 am, so I _________ home early tomorrow morning.
Sorry, sir. I broke the window glass, but I didn’t do that ______.
_______ from space, we can find 70% of the surface of the earth _______ by water.
I really whether we win or lose.