Carlos uses one golf ball to set another golf ball in motion. The following diagram
shows how Carlos designs his experiment.
Carlos releases the ball on the string from
different heights. Each time, the first ball
strikes the second ball, which then rolls
down the track. Which force causes the
first ball to swing downward?
A a pull due to gravity
(B a pull from the string
© a push from Carlos's hand
D friction between air and the golf ball
which force causes the first ball to swing downward?

The number of living organisms in a particular area is

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.

Which of the following describes how binary fission and mitosis are similar? a)they are both used for growth or repair b)they both break down membrane-bound nuclei c)both invoke the replication of a single stand of dna d)both replicate genetic material