If you move,you must inform us___the change of your address
“Sorry” is the hardest word to say sometimes. _______ you know you’ve done something wrong, or something inappropriate, it takes courage to say sorry.
______ for the breakdown of the school computer network, Alice was in low spirits.
With more and more forests disappearing, today the public is much concerned about the way _________.
Without the friction (摩擦力) between feet and the ground, people would ______ be able to walk.
Don’t take his remarks too seriously. He was so sad that I don’t think he really _________ what he was saying.