Answer:
A
Explanation:
they are associated with venous sinuses.this valve open one way flow of direction of the heart.
Answer:
based on the graph the most common gas in the atmosphere would be nitrogen
idk if you want a long answer, but its ketones
Constant speed would have a straight and diagonal line either facing upwards or downwards in the graph. This is because speed is displacement divided by time, which becomes the slope of the graph.