20. The answer is 1 (Precambrian)
21. The answer is 4 (Pennsylvanian)
22. The answer is 2 (Bony Fishes, Dinosaurs, and Mammals)
23. The answer is 2 (Reptiles)
Answer:
Organisms that are more complex, such as eukaryotes, have cells that are specialized for specific functions. Gene regulation needs to be more complex to produce these specialized cells for complex organisms. Please Mark Me Brainliest
Explanation:
The best answer is B - the fish die.
Acid rain flows through soils. If the soil part of a watershed, aluminum is released from the soil and into the streams and lakes located in that watershed.
This lowers the pH in the lake from between 6 and 8 (which is the normal pH in lakes and streams) to less than 5.
Both increase of aluminum and lower pH are directly toxic to fish and they kill off fish populations
The reason of why Brendon experience immense physical pain
and increased craving upon withdrawal because of physical dependence. Physical
dependence is a physical condition that occurs after a gradual drug withdrawal
in which the drug is being chronically used that upon withdrawal, it causes unpleasant
symptoms, mainly, physical.
