What is an indicator that a chemical change has occurred?

A. a change in energy

B. a change in shape

C. the presence of solubility in water

D. the presence of a melting point

Need the answer ASAP! on a test and it's timed

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

answer; i believe the answer is hydraulic action;

the answer is otpion c) understanding

he wants to be heard one more time. he wants to be understood. he needs the truth one more time.

identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.v