Heart problems often cause trouble breathing. which best explains this?
explain why you chooses your answer
a the heart provides the lungs with oxygen.
b the lungs use the circulation caused by the heart
c the lungs are the organs that bring carbon-dioxide into the body
d white blood cells are produced by the lungs

Ricardo notices that when he plays soccer in the rain, his ball does not seem to go as far after a kick. what is the best scientific question that ricardo could ask about this observation? is soccer better played in the rain or sun? how does rain affect the distance a soccer ball can travel? how does rain affect the speed of a soccer ball? is soccer affected by the rain?

In the diagram below, the northern hemisphere would be in what season at position a a.fall b. winter c.summer d.spring

Glucose is broken down in different ways, both in the presence and in the absence of oxygen. using the table for reference, what major products are formed in each reaction set?