Answer:
Because it is made up of organs that act as a system
Explanation:
The integumentary system, skin, has been referred to as a membrane and an organ, but it is more commonly referred to as a system since it contains organs that operate together. Because it surrounds the body and comprises multiple types of tissues and a membrane, it is sometimes considered an organ.
Answer: 1. Headwaters 2. Floodplain 3. Cargo 4. Tributary 5. Keelboats 6. Delta 7. Locks 8. Watersheds 9. Steamboat 10. Silt
Explanation: Hope this helps:)
Answer: radiant, chemical, mechanical, chemical, radiant
Explanation:
Sunlight - electromagnetic energy (radiant)
life - chemical energy
compression - chemical and mechanical energy
retrieve coal - mechanical
burning - chemical, radiant
Answer:
Many scientists favor the RNA world hypothesis, in which RNA, not DNA, was the first genetic molecule of life on Earth. Other ideas include the pre-RNA world hypothesis and the metabolism-first hypothesis. Organic compounds could have been delivered to early Earth by meteorites and other celestial objects