Answer:
hypothesis is an idea or explanation that then test through study and experimentation
Sand , water , and minerals
Answer:
with each heartbeat,the heart pumps blood throughout our bodies,carrying oxygen to every cell,after delivering oxygen the blood returns to the heart the heart then sends the blood to the lungs to pick up more oxygen.
Ammonia synthesis exponentially increased harvests and will continue to do so for years to come. His invention is credited with saving millions of lives and will probably save billions more.