Answer:
hi how are you are you good just asking do not hace the answer
Explanation:
hello
Answer: Probably, harder the mineral it scratches. It makes more sense.
Answer:
See explanation
Explanation:
1. Super Nova
2. Apparent Magnitude
3. One Parsec
4. Cosmology
5. Pulsars
6. Neutron Stars
7. Quasars
8. Brown Dwarf
9. Nebula
10. Constellation
11. Dark Matter or Dark Energy (not sure which one because they are extremely similar and I’m no scientist)
12. Gravity
13. Stellar Evolution
14. Red Shift
PLEASE mark me brainliest I spent 25 minutes working on this for you please and thanks.
The U.S. has more than 87,000 dams greater than six feet high (and two million overall). While many dams continue to provide benefits such as flood control, irrigation, and water supply, for other dams the cost of maintenance or the negative effects on communities, fish, and tribes justifies their removal.
Dam owners and regulators decide whether to remove a dam by weighing many factors including: the cost of removal and the ability to replace any lost power generation against avoided long-term maintenance; safety concerns; benefits to endangered fish populations; increased recreational and commercial fishing; and restoration of cultural values of nearby tribes.
By 2020, roughly 70% of dams will be more than 50 years old, inviting us to reconsider the value to the public of long-term investments in this infrastructure.
