<span>An indicator species is an organism whose presence, absence or abundance reflects a specific environmental condition. Indicator species can signal a change in the biological condition of a particular ecosystem, and thus may be used as a proxy to diagnose the health of an ecosystem. For example, plants or lichens sensitive to heavy metals or acids in precipitation may be indicators of air pollution. Indicator species can also reflect a unique set of environmental qualities or characteristics found in a specific place, such as a unique microclimate. </span>
The answer for "What is petrified wood made of?" would be minerals.
If the coast-to-coast distance is about 2900 miles, it will take about ...
... (2900 mi)/(186000 mi/s) ≈ 15.6 ms
for the signal to travel coast-to-coast at light speed.
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There are time delays due to the amplifiers and repeaters required in the path, and due to the fact that the signals don't actually travel at the speed of light in a wire.
A test of internet speed between Seattle and Washington, DC shows a round-trip time of about 87 ms when traffic is light. Modern communication channels tend to be faster than the telegraph (especially when measured in words per minute).
I don’t even know because I’m in middle school sorry
Answer:
The Antarctica is adversely affected.
Explanation:
Without Antarctic Treaty of 1961, the environment of Antarctica is adversely affected due to using it as a site for testing of weapons by the military forces of different countries. The organisms that lives in that region will be negatively affected causes decline in the population and imbalance of ecosystem as well as extinction of many organism so this treaty provides protection to the Antarctica.
