English is a language that many people around the world ____ not speak perfectly but ____ at least understand.

Where is my ball? I remember I put it here yesterday. --You           it in the wrong place.

It is written clearly in the requirements that all passengers _______ check onto board thirty minutes before the plane takes off．

–Do you know where David is? I couldn’t find him anywhere. – Well. He _____ have gone far — his glasses are still here.

.---I didn't go to work yesterday because my car broke down. ---You ____ mine. I wasn't using it then.