7 While visiting a historical fort, John watched a demonstration of the firing of an old cannon from a distance of 50 m. When
the cannon fired, John heard a loud boom a second later. What was the medium that allowed the sound waves to reach
John?
A the ears
B) the cannon
c) the air
D the ground

The negative impacts of nonnative species generally outweigh the positive impacts

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one

What happens when water’s salinity increases? mass decreases. freezing point decreases. buoyancy of objects decreases. the amount of dissolved minerals decreases.