I put carbon dioxide and circle.
In the photosynthesis question, there was a cork in the beaker to prevent water from evaporating into the surroundings and the rate of photosynthesis is higher than the rate of respiration so the rate of photosynthesis will decrease after the carbon dioxide is used up and the plant needs to respire more to release more carbon dioxide.
Then the shadow question… the metal ball is further away from the screen than the square thingy, so even though when the lines are drawn in the diagram they look about the same size, but actually the circle shadow will be bigger than the square shadow.
JMHO for putting those answers down.