What conclusion can you make about how the carbon dioxide level has changed over time?
the level has not changed.
the level of co2 has declined.
the level of co2 has risen.
the level has reached its maximum.

Always use significant figure rules. remember that these rules apply to all numbers that are measurements. if a vector that is 3 cm long represents 30 km/h, what velocity does a 5 cm long vector which is drawn using the same scale represent? a.100 km/h b.60km/h c.50km/h

Which of the following occurs most often in a population when genetic variation and overproduction are present? some organisms have a lower reproductive success than others. some organisms have a higher reproductive success than others. some organisms have no reproductive success. some organisms do not have genetic variation.

What is the difference between the conducting zone and the respiratory zone of the respiratory system? the conducting zone is a series of cavities and tubes that move air to the respiratory zone where gases exchange with the bloodstream. the conducting zone exchanges gases between the lungs and the alveoli and the respiratory zone is a series of cavities and tubes that move air to the conducting zone. the conducting zone moves oxygen into the cells and the respiratory zone takes carbon dioxide away from the cells. the conducting zone moves oxygen into the bloodstream and the respiratory zone takes carbon dioxide away from the bloodstream.