It would be uracil (C) 
thymine would be complementary to adenine in DNA but because it is RNA it is replaced by uracil.
        
             
        
        
        
Explanation:
Question 1 
Air pollution is the introduction of harmful gases and substances into the atmosphere that renders it unfit for use for life. Some of these toxic gases and particulates are: 
- Carbon monoxide 
- Carbon dioxide
- Nitrogen oxides
- Smoke
- Dust particles 
- Soot
Question 2 
Natural forms are the original nature or outlook of a substance. Examples of natural forms are: 
- Flowers
- Leaves 
- Animals 
- Rocks
- Shells
- Corals 
Question 3
Anthropogenic cause of pollution are human causes of pollution. Some of these are: 
- Combustion of fossil fuels in internal combustion engines release harmful and toxic gases into the atmosphere and causes hair pollution. 
- Improper disposal of waste can produce effluent that reaches the ground water system and other fresh water sources. 
- Noise pollution from airports is very harmful to ear. 
-  Mining activities degrades soil and removes rich fertile soils that should be used for agriculture. 
- Mining wastes can lead to contamination of water bodies around. 
Question 4
Fossil fuels are fuel types that forms from natural process in which organisms are decomposed anaerobically to preserve their energy components. Some of these fuels are: 
Question 5 
- Heart diseases ; ischaemic heart diseases can lead to failure of the heart when it does not receive enough oxygen from the environment. Air pollution contaminates available oxygen in the atmosphere and this is very dangerous to life. 
- Lung cancer: poor air quality can lead to the development of cancerous tumor in the lungs. 
- Asthma: air pollution is one of the leading cause of asthma. 
Other notable mentions are bronchitis, pulmonary diseases, stroke
Question 6
_7 million____ people die each year from air pollution according to the world health organization
Question 7
Air Quality Index(AQI) is an indicator used to express the quality of air in particular area. The AQI can tell the present air quality condition. It can also be used to forecast future air quality in years to come. 
It shows how clean and polluted the air is. 
Question 8
The air quality index uses different colors to alert people about the quality of air. Each color represents different health implication of air quality: 
      Attached image shows the different colors used to alert people of about the air quality.
Question 9
- About 7 million people die annually as a result of air pollution
- Beijing cough is new disease that emanates from the rising air pollution in Beijing
- Asia has the fastest rising cases of air pollution problems. 
- The best way to reduce air pollution is by riding bicycles and walking more. 
Learn more: 
Air pollution brainly.com/question/10743354
#learnwithBrainly
 
        
             
        
        
        
Isotretinoin maybe responsible for depression for depression and suicidal thoughts in the patient. Isotretinoin is very useful against acne, but it can have some severe side effects. Aside for the ones mentioned above, Isotretinoin can also cause birth defects in new-born babies if taken by pregnant women. Liver functionality and cholestrol levels might also be affected, so it is advised to use this medication only under extreme supervision of the doctor.
        
             
        
        
        
Answer:
Colloids or colloidal solutions are mixtures in which microscopically dispersed insoluble particles of one substance are suspended in another substance. The size of the suspended particles in a colloid can range from 1 to 1000 nanometers (10-9 meters).
Hope it helps........
 
        
             
        
        
        
The rotation of Earth on its axis