Answer:
endosymbiosis.
Explanation:
By the beginning of the 20th century, researchers thought that plastids and mitochondria could come from bacteria. These would have been ingested by primitive cells and live within them in symbiosis.
Radiation. radiation is what causes heat, therefore the air would heat from the natural radiation.
Viruses need to be inside a living thing (of course the living thing has to have the right temperature which most living things do) . When they're inside a living thing they start injecting the host's cells with its DNA in order to make more copies of itself which allows the virus to spread. So basically viruses need to be inside something living.
Answer:
Scientists need instruments to measure the world. Instruments and sensors are needed to collect data - that takes engineering to design and build them.
Explanation:
Cause it can kill if you use un-subscribed meds
