Gary lives near an intersection. In his hole, he can hear cars honking. However in his bedroom, he cannot hear any cars honking. In this scenario, the volume of the car honks in Gary’s bedroom fall below his

Expectation
Arbitrary value
Absolute threshold
Upper limit

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

Substances that can pass through cell membranes by diffusion include a. na ions. b. proteins c. glucose. d. oxygen.

The big bang theory suggest that the universe is about - 300 million years old - 4.6 billion years old - 30 billion years old - 13 billion years old