Answer:
B: circulatory system
Explanation:
The circulatory system is made up of blood vessels that carry blood away from and towards the heart. Arteries carry blood away from the heart and veins carry blood back to the heart. The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide.
Scientific theories change because<span> </span>theories<span> may be modified or overturned as new evidence and perspective emerges. ... The process of </span>theory change<span> may take time and involve controversy, but eventually the </span>scientific<span> explanation that is more accurate will be accepted. Hoped you get it!</span>
<span>Answer:
H-C-N H-N-C C-H-N
Notice that C-H-N is the same as N-H-C just written backwards. ( i.e. they have the same connectivtiy.) You can exclude the last one with H in the middle since H has two bonds and 4 electrons around it. At this point you couldn't differentiate between the first two, so I would give you the connectivity in such a problem, which in this case is H-C-N.</span>
Answer:
Physical changes are changes that do not alter the identity of a substance. Chemical changes are changes that occur when one substance is turned into another substance.
Explanation: