1. Air enters the nostrils.
2. Air passes from the trachea to the bronchi
3. Air diffuses from the alveoli to the blood cells.
4. Oxygen enters the blood cells.
5. Blood transports oxygen to other cells.
It is a wels catfish also called sheatfish it also looks like a catfish
Several species or warblers can live in the same spruce tree only because they occupy different nitches within the tree. Hope this helps!
Answer:
Electrons Can Donate - 0
Electrons Can Receive- 2
Valence - 2
Explanation:
The electronic configuration of oxygen is 
. Thus in the p-orbital there is deficiency of two electrons. Hence, it can receive/share electron but it cannot donate electrons. This makes oxygen as a good electron acceptor. Since there is a deficiency of two electrons in the outermost shell of oxygen, the valence of oxygen in thus -2
