What can cause a heart to not function correctly?
A hole in the heart
B running
C Sleeping

The theories on the expansion of galaxies maybe re-examined to strengthen science should not be tested to strengthen science will weaken scientific knowledge if they change will become laws if they don't change

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?