Answer:
(b) Digestive tract and liver
Explanation:
The digestive system consists of the digestive tract and liver. The digestive tract is made up of a large number of parts. These parts include the esophagus, stomach, intestines, rectum, etc. Food enters the mouth and travels down the digestive tract and out passing the rectum. The liver is where the blood passes through and it is responsible for many functions such as the metabolizing of fats and proteins, separating and storing vitamins and minerals, regulating different chemicals found in the blood, etc.
 
        
             
        
        
        
Answer:
C
Explanation:
 They does not carry oxygen to injured areas of tissue
 
        
             
        
        
        
1) B
    (I'm not so sure of this one) All of the other options have a steady impact on population regardless of the density of organisms except competition
2) D
    Increased carbon dioxide levels would not hinder plant growth, and tsunamis aren't really linked to carbon dioxide levels. Increased carbon dioxide is unlikely to lower the air temperature so only D is left.
3) A
4) Three properties of water that allow it to sustain life are that it is adhesive, it is a good solvent, and cohesion. Adhesion is important in situations such as water travelling up xylem tubes in plants so that the water is not pulled down by gravity and can reach parts of the plant that need water. Cohesion allows the water being pulled up the xylem to stay together and for water molecules to be pulled when a neighbouring one is moved. Water being a good solvent allows inorganic minerals to be taken with water through vascular tissue, such as in the previous example.
        
             
        
        
        
Answer:
 haemoglobin
Explanation:
Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body
 
        
             
        
        
        
The answer is; desertification
Topsoil is usually the riches soil in terms of nutrient is important in support of plant vegetation. It is rich because it contains humus and other decomposed materials that recycle nutrients. When the topsoil is washed away, the local region becomes barren in that it cannot support vegetation. This causes the area to turn into a desert.