__________ medical science has achieved control over several dangerous diseases, what worries us is that some of them are returning.
If this product does not give you complete satisfaction, please return it to the manufacturer, stating when it ________.
—David, are you listening to me? —Sorry, Dad. I ________ to make sense of what the reporter said.
—Look! Someone ________ the floor. —Well, it wasn't me. I went shopping just now.
It's said that they ________ a better life ever since they moved to the US.
—Ouch! You hurt me. —I'm sorry. But I ________ any harm. I ________ to drive a rat out.