Answer:
2
Explanation:
Because if you add 1 to 8 you get 9 then subtract 9 by 7 then and your answer is 2
It can be observed and tested
Exhaled air has more carbon dioxide because the blood contains some carbon dioxide (a waste product) that is transferred to the air in the lungs, which is then exhaled. The result is that the exhaled air contains less oxygen and more carbon dioxide than the inhaled air. The air in the lungs also becomes humidified with water before it is exhaled.
An enzyme is a biological molecule that acts as a catalyst in many reactions. They speed up chemical reactions especially the reactions inside living organisms. An enzyme is made up of amino acids. They are known to be very efficient catalysts. Hope this answers the question!
They were similar to modern humans in that they were bipedal (that is, they walked on two legs), but, like apes, they had small brains. Their canine teeth were smaller than those found in apes, and their cheek teeth were larger than those of modern humans.
