1. He knocked over the wine glass and spilled the wine.2. I accidentally knocked over the vase and had to sop up the water with a paper towel.3. The old lady was knocked down by a bus as she crossed the street.
 knock over something knock somebody downknock over something = 把某東西碰倒，例如碰倒花瓶knock over the wine glass = 碰到酒杯，酒杯倒下knock him down = 把他碰倒，例如他被車子碰倒或撞倒
The moderatr of the meeting is not here yet. Does that mean the meeting will not be happening?